Tournament creation

[KnutZuidema]

There's already the game roles, why not add a tournament creator?
It would be used for finding people to play with and creating temporary voice and chat channels for the of each team players that only they can join. It could then be used for automatically putting teams into matches against each other with a finals progression systems.

Usage could look like this:

!tournament <game_role> <team_size> <team_count> <registration_period>

where:
game_role -> the role that should be pinged for finding players
team_size -> the number of players per team
team_count the max number of teams for the tournament

The bot would then create an interaction message like this:

Tournament started for <game> ▶️ 
Registration:
* With a new team: add new reaction
* With an existing team: click on an existing reaction

In this tournament <team_size> players will be playing as a team and
there will be at most **full** <team_count> teams.

Registration ends
if <team_size> **full** teams are found
or
in <registration_period> minutes with all currently full teams

// Maybe countdown or something here?

If we wanted to be even more fancy there's the potential to hook this up to some game APIs to create tournaments for them, if there is enough usage.

[TitusKirch]

For me #5

[KnutZuidema]

Sounds about right. I will start an implementation and we can discuss it in a pull request then.