Add MATS Gym to 3rd party env list.

[axelbr]

Description

Added MATS Gym to the 3rd party environment list.

Type of change

• Documentation

Screenshots

Checklist:

• I have run the pre-commit checks with pre-commit run --all-files (see CONTRIBUTING.md instructions to set it up)
• I have run pytest -v and no errors are present.
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I solved any possible warnings that pytest -v has generated that are related to my code to the best of my knowledge.
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[elliottower]

Cool stuff, thanks for the contribution. Good choice putting it next to the other CARLA Gym project. May be worth mentioning it explicitly in comparison to that, if you want. It looks like the other repo hasn't been updated in 8 months and is a fork of an old gym repo, if you check it and see that it doesn't work or something like that I could remove it. Generally I'd like to have at least semi-maintained projects on that page, not just someone's fork that they made and abandoned.

[axelbr]

Thanks! I will check it out and let you know.

[axelbr]

It worked when I tried it with newer versions of CARLA.