Update Markdown example to use username
Created by: cjwprostar
In the help page for Markdown, the 'Special GitLab references' section doesn't reflect the change to using username instead of user.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Created by: cjwprostar
In the help page for Markdown, the 'Special GitLab references' section doesn't reflect the change to using username instead of user.