Add latest changes from gitlab-org/gitlab@master

doc/administration/monitoring/gitlab_self_monitoring_project/index.md

 # GitLab self monitoring project
 
-NOTE: **Note:**
-This feature is available behind a feature flag called `self_monitoring_project`
-since [12.7](https://gitlab.com/gitlab-org/gitlab/issues/32351). The feature flag
-will be removed once we [add dashboards to display metrics](https://gitlab.com/groups/gitlab-org/-/epics/2367).
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab/issues/32351) behind a disabled feature flag (`self_monitoring_project`) in GitLab 12.7.
+> - The feature flag was removed and the Self Monitoring Project was [made generally available](https://gitlab.com/gitlab-org/gitlab/issues/198511) in GitLab 12.8.
 
 GitLab has been adding the ability for administrators to see insights into the health of
 their GitLab instance. In order to surface this experience in a native way, similar to how

doc/development/documentation/styleguide.md

@@ -540,6 +540,10 @@ Keep heading titles clear and direct. Make every word count. To accommodate sear
 | GitLab Release and Maintenance Policy | This section covers GitLab's Release and Maintenance Policy |
 | Backport to older releases | Backporting to older releases |
 
+NOTE: **Note:**
+If you change an existing title, be careful. Any such changes may affect not only [links](#anchor-links)
+within the page, but may also affect links from GitLab itself, as well as external links, to GitLab documentation.
+
 ### Anchor links
 
 Headings generate anchor links automatically when rendered. `## This is an example`