How to add a notebook from a different folder?

[enryH]

I read that myst-nb relies on myst-parser. I wonder if it is possible to include a notebook similar to a markdown file from the parent folder of the docs folder normally used in Sphinx. I guess this would require to find the correct parser argument whIch I could not find in the documentation:

# index.rst
.. include:: ../README.md
   :parser: myst_parser.sphinx_
   :start-line: 1

The above snippet includes the main repo README into the index / main page of the generated website of Sphinx.

Is there something similar for myst_nb?