Tectonic

• Lowered the minimum Ocean Offset value to -2 instead of -1

• Added the Ultrasmooth option, letting terrain generate smoothly like Tectonic v2.
• Greatly reduced the frequency of lanterns in underground rivers.
• Restructured the mod internally to prepare for v3 for Forge 1.20.

• Updated to 1.21.6
• Raised the cloud height to 256 by default, going even higher to 320 with Increased Height enabled

• Once again re-enabled underground rivers.
• Added support for 1.21.6 pre-release 1. On this version, cloud height is at y256.

Fixed the Increased Height option leaving the terrain height capped at y310, it is now at y630 as intended.