Systems Demo Update - Alpha 1.1.0

From here on out, whenever I'm uploading a new version of any of the game's demos, I'll make an update here.

The Alpha 1.1.0 update for the Systems Demo adds controller support! In addition to keyboard buttons, button prompts are supported for Playstation, Xbox and Nintendo brand controllers. There's also a fallback to a generic, positional button prompts if your controller isn't recognized.

Changelog for everything else:

• Updated the look of the weapon select screen.
• Reformatted the how to play screen and credits.
• Fixed a bug where the truck's stats wouldn't be restored to their defaults upon ending the run.
• Fixed a bug where the pause screen wouldn't function after beating the game.