Updated TODO file

todo.txt

@@ -1,2 +1,4 @@
-1. Implement the networking aspect of the game.
-2. Try to make the ball go between screens.
+1. Implement the multiplayer aspect of the game - detect if M_CLIENT or M_SERVER is set, and perform appropriate actions (e.g. M_CLIENT could control left paddle, M_SERVER could control right paddle).
+2. Fix decoding function - segfaults if code is invalid.
+3. Try to make the ball go between screens.
+