Keyboard "DROP" controls clarification

Upon popular request, the CTRL key now serves as the only way to drop while hanging from a block.

You may still jump up off a block, but now the CTRL key (for keyboard and mouse users) and the B button (Circle for PlayStation controllers) are the only ways to drop directly from a block.

Users can configure their own controls in the settings if they prefer a different key to drop.

I'm open to further feedback, but for now this is the preferred setup from the feedback I've heard.