How do scrimmages work?

Scrimmages use Discord commands to post a host listing, receive challenges, confirm a match, and close the session when finished.

Steps

1. A crew owner starts by using `/scrimmage host` to create a scrimmage listing.
2. Another crew can respond with `/scrimmage request` to challenge the host.
3. The host accepts one request with `/scrimmage accept`, which starts the scrimmage session.
4. Either involved crew owner can end the session with `/scrimmage end`, and the host can also use that flow to cancel before a match starts.
5. Use `/scrimmage status` to review the current listing, requests, or active session details.