Invite user via person in "activity" pane integration

Users who start the repo or post issues appear in the "activity" pane - when you hover/mouseover the nick you get an info panel with several buttons including "remove" - even if this person has never been in or never invited to the chat - but there is no "invite" button here

I suggest adding an "invite" button for users who are not already "in" the room.

Very much required. I see many people comment and open issues. I feel lonely so I like to chat with them but boom :facepunch::boom: ... there is no invite button. It would be really nice to send them a notification via Github to join me in the chat.