Just copy the contrib files

[rhaps0dy]

This PR copies some files from stable-baselines3-contrib. They are the files that #5 modifies.

[dan-pandori]

LGTM, but can you add some more details on the long term plans for these files and the files they are cloned from?

In particular, will these files supersede the old files (meaning that the old files will eventually be deleted)? Or will the two live in parallel indefinitely?

[dan-pandori]

Actually, I just realized that CI is failing for these changes. Was your plan to fix the CI failures as part of this, or in a followup?

[rhaps0dy]

The CI failures should be fixed in #5. The only purpose of this PR is to have a point of reference for #5.

These files will be heavily modified and thus the ability to merge upstream is not helpful. At the same time, upstream has a lot of tests that are just copied from stable-baselines3, so spiritually it's meant to live in this repo.

l these files supersede the old files (meaning that the old files will eventually be deleted)? Or will the two live in parallel indefinitely?

The 'old files' are in https://github.com/rhaps0dy/stable-baselines3-contrib, which will be completely removed from the learned-planners parent repo.