Add initial readthedocs configs

[samjwu]

Place the .readthedocs.yaml in the hip-python directory

[samjwu]

Seems all fine, thanks for adding the RTD config.

Just one question:

As the HIP Python packages are not published yet and not appearing in any of the requirement prescriptions of the RTD script, the build will likely fail or produce empty pages.

Where would we add the hip-python hip-python-as-cuda packages to? To .sphinx/requirements.in, .sphinx/requirements.txt, or to .readthedocs.yaml

The built docs can be seen here: https://rocm.docs.amd.com/projects/hip-python/en/latest/index.html It looks fine, just with the exception of the API pages, which are empty.

Saad made a good point about the documentation changing more often in the source than it would in the PyPi package. My plan is to figure out where the hip-python packages should be added (I suspect it's likely requirements.in) just for getting something working, and later figuring out how to add the Python docs built from source. So far the options I see are adding some custom steps in the .readthedocs.yaml to build the Python packages and add their docs (better solution) or building it and pushing those files to the repository (worse alternative if the custom steps fail).