Update TODO

Switch to cartpole example

Add discrete proximal policy optimization example

Add plotting

Implement a custom PPO example

Add cartpole example from stable baselines3 documentation

Add training programs generated by Gemini

Playing around with reentry trajectory

Version 0.16-1

Minor changes

Increase reference distance for audio

Enable pitch control authority tests

Make pitch angle controllable for speeds above Mach 5.

Put reentry stuff into separate prototype

Add link to Cosmorama space flight simulator