Port to older version (1.21+1)

New features:

• Complete config screen overhaul! Now there are 3 screens, which makes it more user-friendly. Also much more options, descriptions, authors, searching... just check it out!
• Ability to change sounds! Just as quite a lot of people asked for. Now you can choose from any Minecraft built-in sounds
• Ability to change Jade compatibilty. As a few people suggested, were added a button to disable Jade hiding upon advancement toast showing
• Splashes. It isn't about why. It's about why not

Bug fixes:

• Crashes when title/description of advancement is empty
• Sometimes doesn't load custom textures
• Sometimes text doesn't appear when toast shows

Adjustments:

• Added Boosty button in the main config screen
• Changed config system