Add solutions for part 1

projects/11/Pong/Main.jack

@@ -0,0 +1,20 @@
+// This file is part of www.nand2tetris.org
+// and the book "The Elements of Computing Systems"
+// by Nisan and Schocken, MIT Press.
+// File name: projects/11/Pong/Main.jack
+
+/**
+ * The main class of the Pong game.
+ */
+class Main {
+
+    /** Initializes a Pong game and starts running it. */
+    function void main() {
+        var PongGame game;
+        do PongGame.newInstance();
+        let game = PongGame.getInstance();
+        do game.run();
+        do game.dispose();
+        return;
+    }
+}