Improve key binding / controls for PC users

[ivanskodje]

This may be a personal preference, but I do not like the PC controls. It is not good for your hands to use space bar for shooting and up arrow key for jumping. The right hand is completely useless, and should instead be used.

Suggested solution for current player keybindings on PC:
Left Arrow/A: Move Left
Right Arrow/D: Move Right
Space: Jump
Return/Enter, Ctrl, Left Mouse Button: Shoot

This solution will allow people that prefer to use right hand for arrow keys to use Left hand to use CTRL to shoot and space for jumping - and the majority of people that uses left hand, AWSD to move and Space to jump, while shooting using enter/return/lmb to shoot