List of things using PID control loop need more things

[danielflataker]

But a PID isn't only used for cruise control, it can be used for everything that takes an input, desired value, and an output that accelerates the input.

I.e. [autopilot for planes, ..]

I can't think of more things at this moment, but this needs an update soon.

[danielflataker]

Added more stuff.