Update documentation about Factions and McMMO compatibility

[RainOfPain125]

Feature request

• Feature type:
  • [ ] Arena configuration
  • [ ] Classes
  • [ ] Documentation
  • [ ] Economy integration
  • [ ] Leaderboards
  • [ ] New config settings
  • [ ] Other (please explain)
  • [ ] Rewards
  • [X] Third-party plugin support

What does it do?: Add

1 - Support for factions, so that anyone that dies in the Arena does not loose faction power (and configurable how much power they loose in the arena)

2 - Support for McMMO so that people can toggle whether or not earning McMMO EXP in the arena is allowed (or, to a greater extent, make it so that you only get a % of the EXP you would have normally got. IE killing a zombie in the wild gives you 100 xp but killing a zombie in MA would give you 25 xp)

Does it need new or changed commands? What are they?: N/A unless you wanted to make these additions permission-specific IE donators get mobarena.nopowerloss or mobarena.mcmmoexception (which is p2w so pls dont think about that xd)

Does this feature affect other parts of MobArena?: Not that I know of

[ct-martin]

@RainOfPain125 If you use separate worlds then this should be relatively easy. Factions allows you to specify worlds to be excluded from power loss in its config, and if you use a permissions plugin you should be able to use mcMMO's custom experience multiplier with <1 to diminish the amount of XP earned. Unfortunately, I don't know of an easy way to do this when the arena is in the same world.

@jflory7 @garbagemule This would be a good addition to a docs section on playing nicely with other plugins

[garbagemule]

Gonna mark this as a documentation task.