DefinitelyMyCoords

Adds

• Warning when offset isn't aligned with chunks
• Support for Litematica
• Support for Minecraft 1.21.4

Fixes

• Replaced short id 'dmc' with full name 'definitelymycoords' to prevent potential conflicts
• Moved config from 'dmc/config' to 'definitelymycoords/config' (auto-updates)
• F3 Menu flickering whilst editing config
• Text in config menu being hard to read (added background)