Update README.md

Adding 2nd and 3rd levels, changing between levels when player enters door.

Adding player sprite door enter animation and trigger door opening animation simultaneously.

Set up player hitbox and door collision det so player must activate door from center of sprite.

Positioning, animating, and freezing door animation loop until ready to initiate,

Swapping sprites animations for running or idling left or right.

Offset collisionBlock hit detection to the hitbox surrounding player for walls / ceiling / floor.

Rendering hitbox around character sprite image to adjust collision block hit detection.

Rendered and animated king idle sprite at player location.

Increase jump height, refactor update to call collision detection and gravity functions.

Fixed gravity so player can jump while standing on collision block floor.

Fixed collision block detection, adjusted player height and spawn point.

Adding vertical collision block / player hit detection and stopping player movement.

Adding horizontal collision block / player detection and stopping player movement.

Imported collision blocks, created collision block class template and drew collision blocks on level 1 sprite.