M.R.U

• Added support for 1.21.1

• Add's an API function to get ko-fi supporters from "https://api.imb11.dev/v2/kofi"

• Updated to 1.21

• Migrated to stonecutter system.

• Updated to 1.20.6

Full Changelog: https://github.com/IMB11/MRU/compare/0.4.0+1.20.2...0.4.0+1.20.4