2023 release for newer versions of Python and Sphinx

[12rambau]

• [ ] #36
• [ ] maybe refresh the documentation (there are super nice themes out ther in the wild)
• [ ] refresh readme (it's redundant with things in the documentation and I think it could be more synthetic
• [ ] use some linters (black?, ruff?) in the github actions
• [ ] use pre-commits ?
• [ ] aline version support with Sphinx (>3.6) (and get access to hints, f string and other fancy stuff)

Let me know which one you like and I'll do specific PRs