PID Controller visualization

Right now this is very much a brain dump. Its mostly working but features to turn this into a proper learning tool can be added.

Wishlist

• Better car model/animation
• Better road animation (move road instead of looping)
• Improve code editor (maybe move P,I,D outside to prevent mid edit resets?)
• Start off with broken/no PID equation
• Plot all PID terms
• Unify all visual assets into single SVG
• Unify coordinates