Fixes

• Fix broken PvP vulnerable placeholder by @JerichoTorrent in https://github.com/LukeOnuke/pvp-toggle/pull/14
• Fix #15, /pvp now displays the apropriate state.
• Fix #13, placeholder is now functioning.

Refractorings and code

• Changed the way configuration is read, now with a single service ConfigurationService.
• Added documentation to all of the service classes and their methods inside com.lukeonuke.pvptoggle.service.

Full Changelog: https://github.com/LukeOnuke/pvp-toggle/compare/v2.0.1...v3.0.0-alpha.1