Update random functions
Update README
Add test rooms
Replace default dark background behind breakable blocks with pattern
Fix swimming bugs during screen scroll
Add initial variables and checks for run and double jump abilities
More preparations for double jump ability
Implement double jump
Push player away from ceiling during pound up animation
Adjust double jump frame threshold
Initialize sprite frame after setting a animation
Save a few bytes by replacing ld a,0 with xor a
Align player with center of breakable block when pounding and the intial difference is below 3 pixels