Profundis: Nine New Quality Cave Biomes

Sorry about the delay, I had a lot of personal business near the end of the school year, but over the summer I can return to modding some!

Changelog: -Updated to 1.20.1

• New Experimental biome: The Black Caves!
  • Spawn in the same area Amethyst Caves do, but on the other end of the weirdness spectrum.
  • Walls made of Tuff, Deepslate, and Blackstone
  • This biome was inspired by "The Black Mines" in TangoTek's Hermitcraft game Decked Out!
  • DISABLED BY DEFAULT; can be enabled in Config - I need to do a lot of optimization for the new features, I've lost my grace in coding since I've been gone :o
• More ice in the walls of Frozen Caves
• Less amethyst crystals/buds in Amethyst Caves
• No lava springs or lava lakes in Frozen Caves anymore

Technical Changes:

• Reformatted all Configured Features, Placed Features, and Biomes in the JSON format - I didn't code it by hand thank the lord - This is why updating took so long
• The biome layout system now references biome keys that are NOT valid at runtime, which seems to work maybe idk