Added Krush Blokk match 3 game example

Please review and let me know what I screwed up and where! :)

Should only work with `loom use latest --firehose` for now due to the recently merged `OffsetTiledImage` functionality.
Not sure if I should just remove it or add a blurb about this kind of thing being useful for testing, noting the incomplete state it can give you and mentioning the state-saving Loom thing that exists and that's not used for this game.