Register own scenes

[juelg]

There should be a way to register own mujoco scenes in rcs to be used with the scenes string identifier. Perhaps a register function could be used for that.

[pkrack]

How about using gymnasiums environment register? You can register envs with a namespace e.g. rcs or rcs_utn, an env name e.g. lab_hw or lab_sim. During registration you can also specify additional wrappers.

You can then create envs using e.g. gym.make("rcs_utn/lab_hw").
A user wanting to register his own env is then redirected to the gymnasium documentation.

Typically you add the registration hooks to a modules __init__.py. The env rcs_utn/lab_hw is then only available after import rcsss

[juelg]

resolved with #156