Waiting room

[tomatocat]

Is your feature request related to a problem? Please describe.
After a user hosts or joins a game, the game page just tells them to draw. There is no way to indicate the host is waiting for everyone to finish joining before game start.

Describe the solution you'd like
When visiting the game page of a game that hasn't begun yet, or a game the user has not yet joined, the user should be presented with a "waiting room" screen including the people currently in the game, the game settings, and the option to either join the game or wait for game start.

Additional context
TBD. might include design mock ups