Minecraft 1.21 Clean Rebuild

[mmsheeks]

The resource pack has gotten a bit bulky over time, and it's full of custom assets we are no longer using. Since we'll need to be updating the pack for 1.21 anyway, now is a good time to go through and clean things up.

Tasks

• [x] #56
• [x] #57
• [x] #59
• [x] #60

[mmsheeks]

Issue #58 will be held for after the start of the season, see ticket for details.