Begun work on rendering shield

Shield usage now linked to strafe.

You equip a shield, and then you can choose to use/not use it.

If you are using the shield, you will strafe, and you will block attacks
coming from the direction you are facing.

You can attack while shielding, however, you will be "unshielded" for
the duration of your attack.

Rendering doesn't look correct right now.