[Shooter Design] Init, prepare

https://www.youtube.com/watch?v=8mICcBDOL3A 

* Pistol have to be infinite ammo

* projectile enemy with simple walking

* minion enemy with simple walking and close attack

* jumping enemies

* floating enemies

*boar enemies

* second weapon has to be appeared middle of the stage

* health, armor system

* health & armor pickup

* Bullets should be all over the place (not too frequently)

* Shotgun