i added a main menu scene and a score system that is written in GDScript instead of C# for a change. the WallManager, the thing that detects collisions, calls the score method on the ScoreManager.
WallManager binds to the BodyEntered signal on the Area2D class and
detects if the body that entered the area is the ball class, and if it
is, it will reset the ball to its starting position. right now, theres
no scoring system. this will be added later.
