Small Update 1: Audio Sliders

1.) Added audio sliders to let you boost the volume of music and SFX by another 40%.
2.) Fixed an English typo in Chapter 7: "go ourside the circle." -> "go outside the circle."
3.) Fixed a rare stuck bug in the marble game (Chapter 7).
4.) Applied fix to prevent a rare issue where the staircase door in Chapter 8 can knock up the player.