Structures Rebalanced

Surface Mineshaft changes

• 4 new templates for the Surface Mineshaft
  • 2 ladder rooms
  • 1 storeroom
  • 1 barracks
• Reduced amount of coal blocks in coal_room_1
• Miscellaneous other fixes or changes for the Surface Mineshaft
• Attempted improvements at the air/water exposure patch
  • I don't understand why some sections of it just don't change the structure.

Other changes

• Updated pack description to show game version as 1.21
• Added appropriate liquid_settings for all Structures Rebalanced structures