FrozenJoin is a paper plugin which offers Join/Quit actions
which are completely customizable.
TODO: Write something better
Maintained Fork: https://github.com/BlitzOffline/FrozenJoin
Global WIP Version: https://github.com/Frcsty/FrozenJoinGlobal