Structures Rebalanced

• Fixed a few issues with Conquered Stronghold
  • Fixed "conquered" layer (middle layer) room generation, now thin hallway rooms generate.
  • Reduced spawn chance of long corridor in conquered layer

• New structure: Crypt
  • vanilla-esque 5 room dungeon
• New structure: Deepslate/Sculk Dungeon
  • like a dungeon but deepslate and tall

• Added conquered_stronghold
  • This does not replace strongholds
  • Generates over strongholds in Plains, Savanna.

• Cleaned up internals for surface_mineshaft
• surface_mineshaft can now spawn in the biomes listed below:
  • Plains
  • Forest
  • Flower Forest
  • Savanna
  • Old Growth Spruce Taiga
  • Taiga
  • Birch Forest
• New structure: mud_ruin
  • It's like a trail ruin, if not buried.

Initial version.

• dstruct:surface_mineshaft.
  • As it says in the name, it's a mineshaft which has a surface entry.
  • This does not override existing Vanilla mineshafts.

• dstruct:desert_tomb
• Again, what it says in the name.
• Maze-like layout, with good reward.