New Controller Tutorial / Developer Guide

[rland93]

See openjournals/jose-reviews#168 (comment)

Create a tutorial on how Controller interacts with the rest of the simulation to help users create their own, custom controllers.

[rland93]

This is resolved (00e5014)

See: https://rland93.github.io/pendsim/customctl.html for the tutorial.

Part one is shows how to implement a very simple open-loop control policy.

Part two has a few extras, like encouraging the user to explore some of the built-in methods, and shows how to dump intermediate data into the simulation.

I originally started this pendsim project to look at concepts related to Model Predictive Control. So, I whipped up some example MPC code as a tutorial for part 2.