Multi-person messaging

[skitterm]

Description

As a user, I need to be able to communicate with multiple people at the same time, instead of just one-on-one.

Tasks

• Ability to add multiple people to a new room or an existing room
• When a message is sent, all these people are notified
• Room with multiple people shows all participants' names

Acceptance criteria

• Sending a message can send to multiple members