TFC Mantle Mountains

• Removed oceanic and old mountain biomes from being affected.
• Decreased default height scale slightly.
• Added much better terrain height blending so transitions from mountain biomes to others aren't so stark.
• Added volcano scaling.
• Added extended mountain ranges.
• Reworded/renamed some config values to try to make it more readable.

This update is sadly also NOT save safe due to removing some mountain biomes from being affected, any future updates I will make sure are though from now on.