Indy 500 Added

Took way too long (seriously, about a year ago I finished making frogger in less than a month and felt bad that it took so long, and now here I am uploading my first new build in over half a year), but I've got another game in a state worth uploading. It's only got one track so far, but you can race the clock, race against a practically unbeatable computer opponent, or race against a friend. I haven't tested multiplayer much, on account of myself being only a single individual, so let me know if you encounter any issues. Everything *should* work though, since much of the code was able to be copied from my Spacewar! code.

More tracks and game modes coming soon.