2.1.2 (1.21.4)

Modded Nether surface rules now account for the Bedrock ceilings and floors.
Added NetherFrozenBiome, to slightly increase quality of life when making Nether biomes.
Added LargeSpireFeature, a more versatile alternative to LargeDripstoneFeature.
Added CurvingSpikeFeature, a stalagmite-like feature that curves as it gets higher.
Fixed an issue with Removable Item Tags being improperly removed upon shift-clicking.
Moved Wilder Wild's Wind particle to FrozenLib.