Fixed a stray slime at the beginning of Easy

Shuffled the placement of Wyrms and a few mobs near the end section, they should be more accurate to the song notes now! Added some extra apples in the hard difficulty for those struggling near the end.

Also, I cleaned up the Easy difficulty and tried to remove a few notes to make it more readable. It's still chaotic near the chorus, but there should be some more breathing room in the other sections!