Feature: Add `@` to usernames in release text

[klein0r]

e.g. replace - (klein0r) with - (@klein0r) to enable the "contributors" feature in releases:

[AlCalzone]

What about doing it in the changelog when writing it?

[klein0r]

Maybe that will break another process? Like removing the names for the news etc.
see AlCalzone/release-script#158