Users can have discussions about Pubs with other members

[gabestein]

A new (core?) feature: Pubs can be discussed by groups of members in a thread that also sends out emails to Pub Members. This quarter, we should do the most basic version possible. In future quarters, we will expand it to include options that can support different types of review discussion.

Core Assumptions

• Each Pub has a discussion thread that can be added to by all members of the Pub.
• The discussion is rich text and can include file uploads.
• Every time a discussion thread is updated, Pub members get an email notification of the new discussion.
• By replying to the email, Pub members can add to the discussion, similar to GitHub.

Open Questions

• Do child pub thread entries filter up to parent pubs by default? (My working assumption: yes, but only for "editor" members. "Contributor" members only have access to pubs they have explicit access to).
• Do other events show up in the thread log?

Future Considerations

• Multiple discussion threads with specific user permissions, to facilitate multiple types of review.
• On-platform notifications of new thread activity
• How to publish this commentary

Prior Art

https://www.figma.com/proto/2ur4Sz1c80mXezi4n6qv9q/Submissions-%26-Reviews-Workflow?node-id=46-1474