Now that there is a chat in public shares, there should be an easy way to grab the attention of the share owner.

Current situation:

• User A creates a public share and send the link to some people.
• These people (Guests) start writing in the chat.
• User A doesn't notice that there was some activity in the chat until opening the chat tab of that file.

Enhancement:

• Guests can @-mention the share owner (User A).
• When User A is mention, it will automatically join that conversation.