Auto-pause feature

[josejsarmento]

Hey community,

I'm going to try out this docker image, but I would like for it to have some sort of auto-pause feature just like minecraft-docker-server, where after some time without players in the world, the Java process is stopped, but when knocking on the server port (e.g. by the ingame Multiplayer server overview), the process is resumed. The experience for the client is not changed by this. I think this could be an interesting addition to this work.