Allow @tagging within public comments Merged

Currently, it appears @tagging only works within private comments, not public. This is doing a disservice to aha because a huge use case is tasking a coworker for more information or context. This is not the same as a notification email that all subscribers, voters, and watchers get, it is giving someone an action item that you wish them to fulfill. Since this functionality already exists, this request is simply to bring it into public comments.