InvisiLeafs

Initial release for Minecraft 1.20. Also works all the way down to 1.13.

If used in 1.13-1.19.4 though it'll warn about "potential incompatibilities" because of pack_format being higher than expected. To fix that I'd need to make 11 (4-15) unique versions of the same pack with a single number change in them, and I didn't want to do that. It still works this way, just with an annoying red warning you can ignore.