Ability to tag external users in proofing

Many teams in Hive that use and love proofing also collaborate with external approvers, whether that be clients, independent contractors, or other parties.

With this new update, you'll be able to tag an external user in the comments of a proof! This will allow teams to have a conversation via proofing comments about a specific part of a project that requires the proofing visuals.

Thank you to Katie from NYU for requesting this feature!