Add documentation

doc/api/issues.md

@@ -40,7 +40,7 @@ GET /issues?my_reaction_emoji=star
 | `milestone`         | string           | no         | The milestone title. `No+Milestone` lists all issues with no milestone. `Any+Milestone` lists all issues that have an assigned milestone            |
 | `scope`             | string           | no         | Return issues for the given scope: `created_by_me`, `assigned_to_me` or `all`. Defaults to `created_by_me`<br> For versions before 11.0, use the now deprecated `created-by-me` or `assigned-to-me` scopes instead.<br> _([Introduced][ce-13004] in GitLab 9.5. [Changed to snake_case][ce-18935] in GitLab 11.0)_ |
 | `author_id`         | integer          | no         | Return issues created by the given user `id`. Combine with `scope=all` or `scope=assigned_to_me`. _([Introduced][ce-13004] in GitLab 9.5)_          |
-| `assignee_id`       | integer          | no         | Return issues assigned to the given user `id` _([Introduced][ce-13004] in GitLab 9.5)_                                                              |
+| `assignee_id`       | integer          | no         | Return issues assigned to the given user `id`. `None` returns unassigned issues. `Any` returns issues with an assignee. _([Introduced][ce-13004] in GitLab 9.5)_ |
 | `my_reaction_emoji` | string           | no         | Return issues reacted by the authenticated user by the given `emoji` _([Introduced][ce-14016] in GitLab 10.0)_                                      |
 | `iids[]`            | Array[integer]   | no         | Return only the issues having the given `iid`                                                                                                       |
 | `order_by`          | string           | no         | Return issues ordered by `created_at` or `updated_at` fields. Default is `created_at`                                                               |
@@ -154,7 +154,7 @@ GET /groups/:id/issues?my_reaction_emoji=star
 | `milestone`         | string           | no         | The milestone title. `No+Milestone` lists all issues with no milestone                                                                                                           |
 | `scope`             | string           | no         | Return issues for the given scope: `created_by_me`, `assigned_to_me` or `all`.<br> For versions before 11.0, use the now deprecated `created-by-me` or `assigned-to-me` scopes instead.<br> _([Introduced][ce-13004] in GitLab 9.5. [Changed to snake_case][ce-18935] in GitLab 11.0)_ |
 | `author_id`         | integer          | no         | Return issues created by the given user `id` _([Introduced][ce-13004] in GitLab 9.5)_                                         |
-| `assignee_id`       | integer          | no         | Return issues assigned to the given user `id` _([Introduced][ce-13004] in GitLab 9.5)_                                        |
+| `assignee_id`       | integer          | no         | Return issues assigned to the given user `id`. `None` returns unassigned issues. `Any` returns issues with an assignee. _([Introduced][ce-13004] in GitLab 9.5)_ |
 | `my_reaction_emoji` | string           | no         | Return issues reacted by the authenticated user by the given `emoji` _([Introduced][ce-14016] in GitLab 10.0)_                |
 | `order_by`          | string           | no         | Return issues ordered by `created_at` or `updated_at` fields. Default is `created_at`                                         |
 | `sort`              | string           | no         | Return issues sorted in `asc` or `desc` order. Default is `desc`                                                              |
@@ -268,7 +268,7 @@ GET /projects/:id/issues?my_reaction_emoji=star
 | `milestone`         | string           | no         | The milestone title. `No+Milestone` lists all issues with no milestone                                                                                                           |
 | `scope`             | string           | no         | Return issues for the given scope: `created_by_me`, `assigned_to_me` or `all`.<br> For versions before 11.0, use the now deprecated `created-by-me` or `assigned-to-me` scopes instead.<br> _([Introduced][ce-13004] in GitLab 9.5. [Changed to snake_case][ce-18935] in GitLab 11.0)_ |
 | `author_id`         | integer          | no         | Return issues created by the given user `id` _([Introduced][ce-13004] in GitLab 9.5)_                                         |
-| `assignee_id`       | integer          | no         | Return issues assigned to the given user `id` _([Introduced][ce-13004] in GitLab 9.5)_                                        |
+| `assignee_id`       | integer          | no         | Return issues assigned to the given user `id`. `None` returns unassigned issues. `Any` returns issues with an assignee. _([Introduced][ce-13004] in GitLab 9.5)_ |
 | `my_reaction_emoji` | string           | no         | Return issues reacted by the authenticated user by the given `emoji` _([Introduced][ce-14016] in GitLab 10.0)_                |
 | `order_by`          | string           | no         | Return issues ordered by `created_at` or `updated_at` fields. Default is `created_at`                                         |
 | `sort`              | string           | no         | Return issues sorted in `asc` or `desc` order. Default is `desc`                                                              |

doc/api/merge_requests.md

@@ -42,7 +42,7 @@ Parameters:
 | `updated_before`    | datetime | no       | Return merge requests updated on or before the given time                                                              |
 | `scope`             | string   | no       | Return merge requests for the given scope: `created_by_me`, `assigned_to_me` or `all`. Defaults to `created_by_me`<br> For versions before 11.0, use the now deprecated `created-by-me` or `assigned-to-me` scopes instead. |
 | `author_id`         | integer  | no       | Returns merge requests created by the given user `id`. Combine with `scope=all` or `scope=assigned_to_me`              |
-| `assignee_id`       | integer  | no       | Returns merge requests assigned to the given user `id`                                                                 |
+| `assignee_id`       | integer  | no       | Returns merge requests assigned to the given user `id`. `None` returns unassigned merge requests. `Any` returns merge requests with an assignee. |
 | `my_reaction_emoji` | string   | no       | Return merge requests reacted by the authenticated user by the given `emoji` _([Introduced][ce-14016] in GitLab 10.0)_ |
 | `source_branch`     | string   | no       | Return merge requests with the given source branch                                                                     |
 | `target_branch`     | string   | no       | Return merge requests with the given target branch                                                                     |
@@ -166,7 +166,7 @@ Parameters:
 | `updated_before`    | datetime       | no       | Return merge requests updated on or before the given time                                                                      |
 | `scope`             | string         | no       | Return merge requests for the given scope: `created_by_me`, `assigned_to_me` or `all`.<br> For versions before 11.0, use the now deprecated `created-by-me` or `assigned-to-me` scopes instead.<br> _([Introduced][ce-13060] in GitLab 9.5. [Changed to snake_case][ce-18935] in GitLab 11.0)_ |
 | `author_id`         | integer        | no       | Returns merge requests created by the given user `id` _([Introduced][ce-13060] in GitLab 9.5)_                                 |
-| `assignee_id`       | integer        | no       | Returns merge requests assigned to the given user `id` _([Introduced][ce-13060] in GitLab 9.5)_                                |
+| `assignee_id`       | integer        | no       | Returns merge requests assigned to the given user `id`. `None` returns unassigned merge requests. `Any` returns merge requests with an assignee. _([Introduced][ce-13060] in GitLab 9.5)_ |
 | `my_reaction_emoji` | string         | no       | Return merge requests reacted by the authenticated user by the given `emoji` _([Introduced][ce-14016] in GitLab 10.0)_         |
 | `source_branch`     | string   | no       | Return merge requests with the given source branch                                                                     |
 | `target_branch`     | string   | no       | Return merge requests with the given target branch                                                                     |
@@ -279,7 +279,7 @@ Parameters:
 | `updated_before`    | datetime       | no       | Return merge requests updated on or before the given time                                                                      |
 | `scope`             | string         | no       | Return merge requests for the given scope: `created_by_me`, `assigned_to_me` or `all`.<br>                                     |
 | `author_id`         | integer        | no       | Returns merge requests created by the given user `id` _([Introduced][ce-13060] in GitLab 9.5)_                                 |
-| `assignee_id`       | integer        | no       | Returns merge requests assigned to the given user `id` _([Introduced][ce-13060] in GitLab 9.5)_                                |
+| `assignee_id`       | integer        | no       | Returns merge requests assigned to the given user `id`. `None` returns unassigned merge requests. `Any` returns merge requests with an assignee. _([Introduced][ce-13060] in GitLab 9.5)_ |
 | `my_reaction_emoji` | string         | no       | Return merge requests reacted by the authenticated user by the given `emoji` _([Introduced][ce-14016] in GitLab 10.0)_         |
 | `source_branch`     | string   | no       | Return merge requests with the given source branch                                                                     |
 | `target_branch`     | string   | no       | Return merge requests with the given target branch                                                                     |