did some tweaks to make it a better example for newcomers (such as myself)

- the score in the bottom right now updates as you play
- there's an example of using ObjectByName (took me longer than I'd like to disclose to figure out how to get that working) so that people newer to qml as a whole learn it in this example
- made the dialog have a fading animation as well as a timeout to have a live example of using go concurrency to do things in the background (and so you don't need to click it to get it to go away)
- added a new field on blocks so that fast clicking doesn't misalign the blocks and make the game ludicrously difficult to play

- fixed the pre-start click crash with the second commit