AsyncWorldCreation

The plugin has been re-built from scratch as the old version was simply not functional. It is still far from perfect but it now does support basic multi threaded world generation by handling all possible world creation tasks and logic on a separate thread, while keeping the main logic on the main thread. This way the lag spike when creating worlds is slightly reduced, but not fully fixed as bukkit just doesn't support full multithreaded world creation. - changed the command slightly - added world type void - removed developer api - added a config - added support up to 1.21.8