Allow admins to disable @mention for specific strings/usernames

Problem Definition

Some developers often need to type strings like @some-text in their commit and pull request messages. When the text displays, this results in unwanted @ mentions.

Suggested Solution

Users would like to be able to disable @ mentions feature, on a per mentioned user basis.
I.e. specify certain strings that they wouldn't like to result in @ mentions.

Workaround

Current workaround is by writing the @ mention in a code block with backticks, like @some-text