Added LICENSE file

MIT License
Style updates. The game now has a graph-paper style theme and a pencil mouse icon.
Fixed zoom to display better on smaller screens.
Busy icon now displayed when waiting for move.
Big optimizations in strategy. Realized that the AI wasn’t evaluating the heuristics very well, and made a new heuristic that highlights better moves while shunning worse ones.
Added a graphic comparing the before-and-after evaluations of the heuristic function.