[Feature] group conversations

hey! We're looking at integrating a chat system into our app and this looks like it would be a really great fit! Thanks for open sourcing!

Is your feature request related to a problem? Please describe.
We are a mortgage lender looking to offer mortgages to groups of people. Ideally we'd like to be able to have group conversations, where an operator or customer could add another user to their conversation.

Describe the solution you'd like
I've not looked at the code in too much detail but wondering how feasible this would be?

Describe alternatives you've considered
We've looked at paid alternatives like Intercom, i'd be great to build on something we can customise and push features upstream though.

Additional context