Add ability to enable Single GUI in config.
Add configurable admin and player method (in config) that will open GUI with GameModes.
Add ability to define default player GameMode GUI.
Add new commands that will process config options.
Add dependencies to AcidIsland and BSkyBlock addons in pom.xml.
Use proper way how to get GameMode admin and user commands.
Init Settings object and implement onReload() method.
Add check on disabled game modes, to avoid loading challenges in addons, where it should be disabled by settings.