Add paddle to the game.

Add paddle to the game.
Mouse input will make the paddle move horizonatlly.
Add ball to the game.

The ball does nothing as of now.
Make the ball move along with paddle initially.
When left clicked, release the ball.

Into infinity and beyond! (FIX THIS ;))
Ball bounces off the walls now.

TODO: Bounce it off Paddle!
Ball now reacts to the paddle but paddle moves too!

TODO: Paddle should not bounce off when it gets hit by the ball!

Maybe an interesting idea! ;)
Paddle does not move now.

TODO: Ball does not bounce off the right wall! :-/
Remove the css style applied on game_div.
Fix: Keep the ball and Padle within bounds!