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.
I find it's often good practice in "production code" to make anonymous callbacks local private functions instead. It is often easier to debug and reason about. Can you refactor this?