Update README.md

Fix example reference

README.md

@@ -36,7 +36,7 @@ Usage
 
 See `examples/`, and the documentation, which can be rendered using `cargo doc`.
 
-For a more complete example, see [a minesweeper implementation](https://github.com/redox-os/games-for-redox/blob/master/src/minesweeper.rs), that I made for Redox using termion.
+For a more complete example, see [a minesweeper implementation](https://github.com/redox-os/games-for-redox/blob/master/src/minesweeper/main.rs), that I made for Redox using termion.
 
 <img src="image.png" width="150">