Sloppy Tanks update

This describes a minor update to Sloppy Tanks. The changes are mostly quality of life improvements. These include:

• Missiles are now much faster and the time to reload is much shorter. This makes the game more dynamic.
• Reloading visualisation. Now you can know exactly when the tank can shoot the next missile.
• Shooting sound was updated. It should play much better with the background music.
• Now sounds for tank hitting a wall and for the bullet hitting a wall.
• Tank destruction particles. Tanks don't just vanish when are destroyed.
• Tanks wobble a bit when they hit a wall.