Changes:
- Added pressure plate
- Added dark wood and leaves
- Shortened noteblock audio so more notes can be played in parallel
- Implemented support for 3 saves
- Implemented new worldgen:
- Added shrubs
- Added wide and flat trees
- Added dark tall trees
- Added forest biome
- Repeaters now take one tick to propagate the signal
- Fixed a crash when exiting the game with no modified chunks