Add "minesweeper" example game

[philipnorton42]

Add a blue token to the game grid in a blank spot.
Add a red token to the game grid in a blank spot.

If the user clicks on a red spot the game is over.
If the user clicks on a blue token remove the token and increment the score.

In the update handler, add a token to the board based on the score of the user. Do not exceed this limit.

[philipnorton42]

I've called it 'fort'.