README.rst mentions Sphinx for generating docs, but it actually uses MkDocs

The 'README.rst' file states that the py-template template uses Sphinx for generating documentation:

```rst
- Documentation with Sphinx_ and `Read the Docs`_ using the furo_ theme
```
**NOTE** that there is actually no link for Sphinx, or furo theme for Sphinx.

But actually, the py-template uses **[MkDocs](https://www.mkdocs.org/)**, as seen by the fact that the template generates `mkdocs.yml` file (which looks like it didn't fill the correct values, as it still refers to iterative and py-template), and that the `docs/gen_ref_pages.py` uses `mkdocs_gen_file` module.

Not [Sphinx](https://www.sphinx-doc.org/).

Please fix the README, as follows... or make the template use Sphinx with furo theme, as stated in the README.
```rst
- Documentation with MkDocs_ and `Read the Docs`_ using the material_ theme

.. _material: https://squidfunk.github.io/mkdocs-material/
.. _MkDocs: https://www.mkdocs.org/
.. _Read the Docs: https://readthedocs.org/
```