Screenshake!

Hey y'all, I've replaced and fixed a few things this update and added screenshake to certain things.

Added screenshake to guns and taking damage

Replaced the gun sound placeholders with new placeholder sounds from Enter the Gungeon that fit a bit better. Sadly, this means no more pew sound effect :(

Replaced the main menu background image and added splash text

"Fixed" the RPG not animating properly when being fired. Though if you try to fire it within like 0.25s it'll trigger the cooldown for some reason

Fixed going into forest endless mode before loading warehouse causing the scene to load incorrectly

 Fixed the medkits cooldown being triggered if the player tries to use it at full health

Did some other stuff I prob forgor ¯\_(ツ)_/¯