Broken link to Sphinx rst docs

[SJaffa]

In the following line you reference the Sphinx reStructuredText Primer but that link is broken, I think it should be https://www.sphinx-doc.org/en/master/usage/restructuredtext/basics.html

https://github.com/lutraconsulting/MDAL/blob/0382ca703ead5928e9d25244efc251a3860f58c5/docs/source/contributing/rst_style.rst?plain=1#L7

Thanks :)