Dev bot commands

[Qaomen]

Description
Once the server is running, there is no easy way to influence configuration options or alter the state of the game (e.g. resetting a race). Some dev-only bot commands could be useful here!
Player commands would be nice to have in the future as well, but these won't be part of this issue.

Minimum Acceptance Criteria

• A command to reset a race (similar to !end but without considering the race finished w/ a database entry & points).
• Commands to kick and/or ban a user.
• Commands to alter marble rules (max marbles, enter/dnf timeouts, auto-joined bot count etc).
• The bot should display a message for commands involving configurable values, to confirm and/or read the current value.

[Zemanzo]

Useful guide for setting up something proper: https://discordjs.guide/command-handling/#individual-command-files