Cavernous-X-Patched

Updated to Cavernous 2.1.3 to support Minecraft 1.21 Also figured out an issue that was causing the pack not to work if you didn't have a datapack that had an overworld.json to patch by adding a separate datapack with the vanilla values to load separately.

The "resource pack" is actually this vanilla datapack to allow the patching to work correctly if you don't meet the previous condition.