Merge branch 'jh-real-time-sidebar-docs' into 'master'

Docs: Document Real-Time sidebar as production-ready

See merge request gitlab-org/gitlab!40500

doc/user/project/issues/index.md

@@ -112,8 +112,6 @@ and modify them if you have the necessary [permissions](../../permissions.md).
 #### Real-time sidebar **(CORE ONLY)**
 
 > - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/17589) in GitLab 13.3.
-> - It cannot be enabled or disabled per-project.
-> - It's not recommended for production use.
 
 Assignees in the sidebar are updated in real time. This feature is **disabled by default**.
 To enable, you need to enable [ActionCable in-app mode](https://docs.gitlab.com/omnibus/settings/actioncable.html).