Audio Update

Added music, sound effects, Added level 4, and fixed a few bugs.

Note: level 4 is currently not released its still a work in progress

Music:
- Unreal starter music
- 001 💜 Heartbound OST 💛 Overture

Sound effects:
Jump, death, door locked, key pickup - made by me in BFXR, or recorded
Checkpoint, moving platforms, door open/close- pixabay.com
https://pixabay.com/sound-effects/get-me-out-79760/
https://pixabay.com/sound-effects/burning-fire-steam-87118/
https://pixabay.com/sound-effects/door-open-close-45475/