Merge branch 'docs/highlight-mentions' into 'master'

Document highlighted mentions

See merge request gitlab-org/gitlab-ce!22488

doc/user/project/issues/issues_functionalities.md

@@ -118,9 +118,12 @@ is the `project-name`, and `xxx` is the issue number.
 
 #### 13. @mentions
 
-- Mentions: you can either `@mention` a user or a group present in your
-GitLab instance and they will be notified via todos and email, unless that
-person has disabled all notifications in their profile settings.
+- You can either `@mention` a user or a group present in your
+  GitLab instance and they will be notified via todos and email, unless that
+  person has disabled all notifications in their profile settings.
+- Mentions for yourself (the current logged in user),will be distinctly highlighted
+  in a different color, allowing you to easily see which comments involve you,
+  helping you focus on them quickly.
 
 To change your [notification settings](../../../workflow/notifications.md) navigate to
 **Profile Settings** > **Notifications** > **Global notification level**