add example game

README.md

@@ -5,3 +5,22 @@
 ``` bash
 pip install git+https://github.com/WaylonWalker/pygame-starter
 ```
+
+## Example Game
+
+You can make a quick game by inheriting from Game, and calling
+`.run()`.  This example just fills the screen with an aqua color, but
+you can put all of your game logic in the `game` method.
+
+``` python
+from pygame_starer import Game
+
+class MyGame(Game):
+    def game(self):
+        self.screen.fill((128, 255, 255))
+
+if __name__ == "__main__":
+    game = MyGame()
+    game.run()
+
+```