Add documentation to list the compliance violation severity levels

Adds two tables to the merge request compliance violations
documentation. The first is the severity level scale with iconography.
The second is a list of the possible violations and their introduction
status.

doc/user/compliance/compliance_report/index.md

@@ -108,7 +108,8 @@ The remaining records are truncated when this limit is reached.
 
 ## Merge request violations
 
-> Introduced in GitLab 14.6. [Deployed behind the `compliance_violations_report` flag](../../../administration/feature_flags.md). Disabled by default.
+> - Introduced in GitLab 14.6. [Deployed behind the `compliance_violations_report` flag](../../../administration/feature_flags.md). Disabled by default.
+> - GraphQL API [introduced](https://gitlab.com/groups/gitlab-org/-/epics/7222) in GitLab 14.9.
 
 FLAG:
 On self-managed GitLab, by default this feature is not available. To make it available,
@@ -123,10 +124,10 @@ that exist in projects in a specific group. For each separation of duties compli
 - Reason for the compliance violation.
 - A link to the merge request that caused the compliance violation.
 
-Merge request violations can only be access in the GitLab UI, but issues are tracking adding:
+Merge request violations can be accessed:
 
-- [A GraphQL type to allow retrieval of compliance violations](https://gitlab.com/gitlab-org/gitlab/-/issues/347325).
-- [Consuming the merge request violations GraphQL type in the user interface](https://gitlab.com/gitlab-org/gitlab/-/issues/342897).
+- In the GitLab UI.
+- Using the [GraphQL API](../../../api/graphql/reference/index.md#complianceviolation) (GitLab 14.9 and later).
 
 ### View merge request violations
 
@@ -134,3 +135,34 @@ To view merge request violations:
 
 1. On the top bar, select **Menu > Groups** and find your group.
 1. On the left sidebar, select **Security & Compliance > Compliance report**.
+
+### Severity levels scale
+
+The following is a list of available violation severity levels, ranked from most to least severe:
+
+| Icon                                          | Severity level |
+|:----------------------------------------------|:---------------|
+| **{severity-critical, 18, gl-fill-red-800}**  | Critical       |
+| **{severity-high, 18, gl-fill-red-600}**      | High           |
+| **{severity-medium, 18, gl-fill-orange-400}** | Medium         |
+| **{severity-low, 18, gl-fill-orange-300}**    | Low            |
+| **{severity-info, 18, gl-fill-blue-400}**     | Info           |
+
+### Violation types
+
+The following is a list of violations that are either:
+
+- Already available.
+- Aren't available, but which we are tracking in issues.
+
+| Violation                            | Severity level  | Category                                                                                | Description                                                                                                                                                                                      | Availability                                                        |
+|:-------------------------------------|:----------------|:----------------------------------------------------------------------------------------|:-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|:--------------------------------------------------------------------|
+| Author approved merge request        | High            | [Separation of duties](#approval-status-and-separation-of-duties)                       | The author of the merge request approved their own merge request. [Learn more](../../project/merge_requests/approvals/settings.md#prevent-approval-by-author).                                   | [Unavailable](https://gitlab.com/groups/gitlab-org/-/epics/6870)    |
+| Committers approved merge request    | High            | [Separation of duties](#approval-status-and-separation-of-duties)                       | The committers of the merge request approved the merge request they contributed to. [Learn more](../../project/merge_requests/approvals/settings.md#prevent-approvals-by-users-who-add-commits). | [Unavailable](https://gitlab.com/groups/gitlab-org/-/epics/6870)    |
+| Fewer than two approvals             | High            | [Separation of duties](#approval-status-and-separation-of-duties)                       | The merge request was merged with fewer than two approvals. [Learn more](../../project/merge_requests/approvals/rules.md).                                                                       | [Unavailable](https://gitlab.com/groups/gitlab-org/-/epics/6870)    |
+| Pipeline failed                      | Medium          | [Pipeline results](../../../ci/pipelines/index.md)                                      | The merge requests pipeline failed and was merged.                                                                                                                                               | [Unavailable](https://gitlab.com/gitlab-org/gitlab/-/issues/346011) |
+| Pipeline passed with warnings        | Info            | [Pipeline results](../../../ci/pipelines/index.md)                                      | The merge request pipeline passed with warnings and was merged.                                                                                                                                  | [Unavailable](https://gitlab.com/gitlab-org/gitlab/-/issues/346011) |
+| Code coverage down more than 10%     | High            | [Code coverage](../../../ci/pipelines/settings.md#merge-request-test-coverage-results)  | The code coverage report for the merge request indicates a reduction in coverage of more than 10%.                                                                                               | [Unavailable](https://gitlab.com/gitlab-org/gitlab/-/issues/346011) |
+| Code coverage down between 5% to 10% | Medium          | [Code coverage](../../../ci/pipelines/settings.md#merge-request-test-coverage-results)  | The code coverage report for the merge request indicates a reduction in coverage of between 5% to 10%.                                                                                           | [Unavailable](https://gitlab.com/gitlab-org/gitlab/-/issues/346011) |
+| Code coverage down between 1% to 5%  | Low             | [Code coverage](../../../ci/pipelines/settings.md#merge-request-test-coverage-results)  | The code coverage report for the merge request indicates a reduction in coverage of between 1% to 5%.                                                                                            | [Unavailable](https://gitlab.com/gitlab-org/gitlab/-/issues/346011) |
+| Code coverage down less than 1%      | Info            | [Code coverage](../../../ci/pipelines/settings.md#merge-request-test-coverage-results)  | The code coverage report for the merge request indicates a reduction in coverage of less than 1%.                                                                                                | [Unavailable](https://gitlab.com/gitlab-org/gitlab/-/issues/346011) |