Update API docs to reflect new issuable text limits

Instead of 1,000,000 characters, we increased the limit to 1 megabyte
(https://gitlab.com/gitlab-org/gitlab/merge_requests/18605), which is
1,048,576 bytes.

Closes https://gitlab.com/gitlab-org/gitlab/issues/34172

doc/api/epics.md

@@ -170,7 +170,7 @@ POST /groups/:id/epics
 | `id`                | integer/string   | yes        | The ID or [URL-encoded path of the group](README.md#namespaced-path-encoding) owned by the authenticated user                |
 | `title`             | string           | yes        | The title of the epic |
 | `labels`            | string           | no         | The comma separated list of labels |
-| `description`       | string           | no         | The description of the epic. Limited to 1 000 000 characters.  |
+| `description`       | string           | no         | The description of the epic. Limited to 1,048,576 characters.  |
 | `start_date_is_fixed` | boolean        | no         | Whether start date should be sourced from `start_date_fixed` or from milestones (since 11.3) |
 | `start_date_fixed`  | string           | no         | The fixed start date of an epic (since 11.3) |
 | `due_date_is_fixed` | boolean          | no         | Whether due date should be sourced from `due_date_fixed` or from milestones (since 11.3) |
@@ -237,7 +237,7 @@ PUT /groups/:id/epics/:epic_iid
 | `id`                | integer/string   | yes        | The ID or [URL-encoded path of the group](README.md#namespaced-path-encoding) owned by the authenticated user                |
 | `epic_iid`          | integer/string   | yes        | The internal ID  of the epic  |
 | `title`             | string           | no         | The title of an epic |
-| `description`       | string           | no         | The description of an epic. Limited to 1 000 000 characters.  |
+| `description`       | string           | no         | The description of an epic. Limited to 1,048,576 characters.  |
 | `labels`            | string           | no         | The comma separated list of labels |
 | `start_date_is_fixed` | boolean        | no         | Whether start date should be sourced from `start_date_fixed` or from milestones (since 11.3) |
 | `start_date_fixed`  | string           | no         | The fixed start date of an epic (since 11.3) |

doc/api/issues.md

@@ -58,7 +58,7 @@ GET /issues?confidential=true
 | `updated_after`     | datetime         | no         | Return issues updated on or after the given time                                                                                                    |
 | `updated_before`    | datetime         | no         | Return issues updated on or before the given time                                                                                                   |
 | `confidential`      | Boolean          | no         | Filter confidential or public issues.                                                                                                               |
-| `not`               | Hash             | no         | Return issues that do not match the parameters supplied. Accepts: `labels`, `milestone`, `author_id`, `author_username`, `assignee_id`, `assignee_username`, `my_reaction_emoji`, `search`, `in` |  
+| `not`               | Hash             | no         | Return issues that do not match the parameters supplied. Accepts: `labels`, `milestone`, `author_id`, `author_username`, `assignee_id`, `assignee_username`, `my_reaction_emoji`, `search`, `in` |
 
 ```bash
 curl --header "PRIVATE-TOKEN: <your_access_token>" https://gitlab.example.com/api/v4/issues
@@ -207,7 +207,7 @@ GET /groups/:id/issues?confidential=true
 | `updated_after`     | datetime         | no         | Return issues updated on or after the given time                                                                              |
 | `updated_before`    | datetime         | no         | Return issues updated on or before the given time                                                                             |
 | `confidential`     | Boolean          | no         | Filter confidential or public issues.                                                                                         |
-| `not`               | Hash             | no         | Return issues that do not match the parameters supplied. Accepts: `labels`, `milestone`, `author_id`, `author_username`, `assignee_id`, `assignee_username`, `my_reaction_emoji`, `search`, `in` |  
+| `not`               | Hash             | no         | Return issues that do not match the parameters supplied. Accepts: `labels`, `milestone`, `author_id`, `author_username`, `assignee_id`, `assignee_username`, `my_reaction_emoji`, `search`, `in` |
 
 ```bash
 curl --header "PRIVATE-TOKEN: <your_access_token>" https://gitlab.example.com/api/v4/groups/4/issues
@@ -605,7 +605,7 @@ POST /projects/:id/issues
 | `id`                                      | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `iid`                                     | integer/string | no       | The internal ID of the project's issue (requires admin or project owner rights) |
 | `title`                                   | string         | yes      | The title of an issue |
-| `description`                             | string         | no       | The description of an issue. Limited to 1 000 000 characters. |
+| `description`                             | string         | no       | The description of an issue. Limited to 1,048,576 characters. |
 | `confidential`                            | boolean        | no       | Set an issue to be confidential. Default is `false`.  |
 | `assignee_ids`                            | integer array  | no       | The ID of a user to assign issue |
 | `milestone_id`                            | integer        | no       | The global ID of a milestone to assign issue  |
@@ -707,7 +707,7 @@ PUT /projects/:id/issues/:issue_iid
 | `id`           | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `issue_iid`    | integer | yes      | The internal ID of a project's issue                                                                       |
 | `title`        | string  | no       | The title of an issue                                                                                      |
-| `description`  | string  | no       | The description of an issue. Limited to 1 000 000 characters.        |
+| `description`  | string  | no       | The description of an issue. Limited to 1,048,576 characters.        |
 | `confidential` | boolean | no       | Updates an issue to be confidential                                                                        |
 | `assignee_ids` | integer array | no | The ID of the user(s) to assign the issue to. Set to `0` or provide an empty value to unassign all assignees. |
 | `milestone_id` | integer | no       | The global ID of a milestone to assign the issue to. Set to `0` or provide an empty value to unassign a milestone.|

doc/api/merge_requests.md

@@ -897,7 +897,7 @@ POST /projects/:id/merge_requests
 | `title`                    | string  | yes      | Title of MR                                                                     |
 | `assignee_id`              | integer | no       | Assignee user ID                                                                |
 | `assignee_ids`             | integer array | no | The ID of the user(s) to assign the MR to. Set to `0` or provide an empty value to unassign all assignees.  |
-| `description`              | string  | no       | Description of MR. Limited to 1 000 000 characters. |
+| `description`              | string  | no       | Description of MR. Limited to 1,048,576 characters. |
 | `target_project_id`        | integer | no       | The target project (numeric id)                                                 |
 | `labels`                   | string  | no       | Labels for MR as a comma-separated list                                         |
 | `milestone_id`             | integer | no       | The global ID of a milestone                                                           |
@@ -1050,7 +1050,7 @@ PUT /projects/:id/merge_requests/:merge_request_iid
 | `assignee_ids`             | integer array | no | The ID of the user(s) to assign the MR to. Set to `0` or provide an empty value to unassign all assignees.  |
 | `milestone_id`             | integer | no       | The global ID of a milestone to assign the merge request to. Set to `0` or provide an empty value to unassign a milestone.|
 | `labels`                   | string  | no       | Comma-separated label names for a merge request. Set to an empty string to unassign all labels.                    |
-| `description`              | string  | no       | Description of MR. Limited to 1 000 000 characters. |
+| `description`              | string  | no       | Description of MR. Limited to 1,048,576 characters. |
 | `state_event`              | string  | no       | New state (close/reopen)                                                        |
 | `remove_source_branch`     | boolean | no       | Flag indicating if a merge request should remove the source branch when merging |
 | `squash`                   | boolean | no       | Squash commits into a single commit when merging |

doc/api/notes.md

@@ -113,7 +113,7 @@ Parameters:
 
 - `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding)
 - `issue_iid` (required) - The IID of an issue
-- `body` (required) - The content of a note. Limited to 1 000 000 characters.
+- `body` (required) - The content of a note. Limited to 1,000,000 characters.
 - `created_at` (optional) - Date time string, ISO 8601 formatted, e.g. 2016-03-11T03:45:40Z (requires admin or project/group owner rights)
 
 ```bash
@@ -133,7 +133,7 @@ Parameters:
 - `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding)
 - `issue_iid` (required) - The IID of an issue
 - `note_id` (required) - The ID of a note
-- `body` (required) - The content of a note. Limited to 1 000 000 characters.
+- `body` (required) - The content of a note. Limited to 1,000,000 characters.
 
 ```bash
 curl --request PUT --header "PRIVATE-TOKEN: <your_access_token>" https://gitlab.example.com/api/v4/projects/5/issues/11/notes?body=note
@@ -231,7 +231,7 @@ Parameters:
 
 - `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding)
 - `snippet_id` (required) - The ID of a snippet
-- `body` (required) - The content of a note. Limited to 1 000 000 characters.
+- `body` (required) - The content of a note. Limited to 1,000,000 characters.
 - `created_at` (optional) - Date time string, ISO 8601 formatted, e.g. 2016-03-11T03:45:40Z
 
 ```bash
@@ -251,7 +251,7 @@ Parameters:
 - `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding)
 - `snippet_id` (required) - The ID of a snippet
 - `note_id` (required) - The ID of a note
-- `body` (required) - The content of a note. Limited to 1 000 000 characters.
+- `body` (required) - The content of a note. Limited to 1,000,000 characters.
 
 ```bash
 curl --request PUT --header "PRIVATE-TOKEN: <your_access_token>" https://gitlab.example.com/api/v4/projects/5/snippets/11/notes?body=note
@@ -354,7 +354,7 @@ Parameters:
 
 - `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding)
 - `merge_request_iid` (required) - The IID of a merge request
-- `body` (required) - The content of a note. Limited to 1 000 000 characters.
+- `body` (required) - The content of a note. Limited to 1,000,000 characters.
 - `created_at` (optional) - Date time string, ISO 8601 formatted, e.g. 2016-03-11T03:45:40Z
 
 ### Modify existing merge request note
@@ -370,7 +370,7 @@ Parameters:
 - `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding)
 - `merge_request_iid` (required) - The IID of a merge request
 - `note_id` (required) - The ID of a note
-- `body` (required) - The content of a note. Limited to 1 000 000 characters.
+- `body` (required) - The content of a note. Limited to 1,000,000 characters.
 
 ```bash
 curl --request PUT --header "PRIVATE-TOKEN: <your_access_token>" https://gitlab.example.com/api/v4/projects/5/merge_requests/11/notes?body=note
@@ -472,7 +472,7 @@ Parameters:
 | --------- | -------------- | -------- | ----------- |
 | `id`      | integer/string | yes | The ID or [URL-encoded path of the group](README.md#namespaced-path-encoding) |
 | `epic_id` | integer | yes  | The ID of an epic |
-| `body`    | string  | yes  | The content of a note. Limited to 1 000 000 characters. |
+| `body`    | string  | yes  | The content of a note. Limited to 1,000,000 characters. |
 
 ```bash
 curl --request POST --header "PRIVATE-TOKEN: <your_access_token>" https://gitlab.example.com/api/v4/projects/5/snippet/11/notes?body=note
@@ -493,7 +493,7 @@ Parameters:
 | `id`      | integer/string | yes | The ID or [URL-encoded path of the group](README.md#namespaced-path-encoding) |
 | `epic_id` | integer | yes  | The ID of an epic |
 | `note_id` | integer | yes  | The ID of a note |
-| `body`    | string  | yes  | The content of a note. Limited to 1 000 000 characters. |
+| `body`    | string  | yes  | The content of a note. Limited to 1,000,000 characters. |
 
 ```bash
 curl --request PUT --header "PRIVATE-TOKEN: <your_access_token>" https://gitlab.example.com/api/v4/projects/5/snippet/11/notes?body=note