Added anti-afk plugin.

After roughly 20 minutes of being AFK you will be kicked From the 10 minute mark onward you will get warnings every 2 minutes

I didn’t want to have to implement this but unfortunately the server dropped from 20 to 11 tps due to an afk farm, so to prevent this from happening again I’ve added this.

If this amount of time end up being too short I will extend it

If you find any bugs or issues after this update please report them in <#723932206837399574>