Update some of my sample projects

[DNin01]

Box2D:

• Added a "README" comment.

Moving Around with Pointer Lock (Pointerlock):

• The pointer lock/movement handler is now in a separate sprite.

Recolor the Dango (Color Picker):

• Added a "Credits" sprite.

Tweening:

• The animation now loops. (It's a broadcast message script so you don't need to restart the script to update it when the compiler is enabled)

All:

• Credited Twemoji for the Dango.