Add NumberSections - number each markdown document from 1

[72757373656c6c]

In the MySt-Parser documentation on github, the conf.py contains a section "Local Sphinx extensions".

There are at least two modules that are of interest:

1. MystExampleDirective
2. NumberSections

Unlike toctree numbered and Sphinx-multitoc-numbering, I'm looking to number each autonomous markdown document starting at 1, similar to this and the myst-parser documentation itself.

NumberSections above is perfect. If it numbered the document headers in the "Secondary Sidebar" it would be more perfect 😄

When I researched NumberSections I found a github entry. The issue is unrelated, but the author of the post showed an example of their documents' front-matter that contained "numberSections: true". They were referencing JupyterBooks, so I did a site search at jupyterbook.org, but there were no results. I tried it, and it did not number the document's headings and there was no error.

So I'm back to these modules, are these modules "standard" or is there a more official way?

Would it be a Feature Request to make NumberSections, as used in the MyST-Parser documentation, official? Same goes for MystExampleDirective?

Thank you in advance.

Environment: Sphinx + myst-parser + sphinx-book-theme