Add a documentation website

[crnh]

Proposed change

This PR adds documentation (to be hosted on readthedocs) as requested in #35. In its current state, the documentation imports the README and example notebooks. Additionally, compatibility information and the docstrings for the public parts of the API are included. The documentation is generated using Sphinx, and mainly written in markdown using MyST

In the future, we want to split the information in the README over different pages (e.g. "getting started" and multiple pages demonstrating the functionalities of ZOSPy). Furthermore, we would like to add several tutorials explaining how to add new analyses etc.

Other changes that are part of this PR:

• GitHub pages has been disabled and the project website has been changed to https://zospy.readthedocs.io
• Many missing docstrings were added (mainly in zpcore)
• Module docstrings were added or extended, as these are very useful when automatically generating the API documentation. This is a work in progress, and several modules still need better documentation.

Type of change

• [ ] Example (a notebook demonstrating how to use ZOSPy for a specific application)
• [ ] Bugfix (non-breaking change which fixes an issue)
• [ ] New analysis (a wrapper around an OpticStudio analysis)
• [ ] New feature (other than an analysis)
• [ ] Breaking change (fix/feature causing existing functionality to break)
• [ ] Code quality improvements to existing code or addition of tests
• [x] Documentation

Additional information

• Python version: ...
• OpticStudio version: ...

Related issues

Closes #35

Checklist

• [x] I have followed the contribution guidelines
• [x] The code has been linted, formatted and tested locally using tox.
• [x] Local tests pass. Please fix any problems before opening a PR. If this is not possible, specify what doesn't work and why you can't fix it.
• [ ] I added new tests for any features contributed, or updated existing tests.
• [ ] I updated CHANGELOG.md with my changes (except for refactorings and changes in the documentation).

If you contributed an analysis:

• [ ] I did not use AttrDicts for the analysis result data (please use dataclasses instead).

If you contributed an example:

• [ ] I contributed my example as a Jupyter notebook.

⚠️ ReadTheDocs is currently building the documentation from this branch. Please do not merge it before ReadTheDocs has been instructed to build the documentation from main.

[LucVV]

If we change it to built the docs from main, merging should be fine!