I'm writing a primitive exporter for jupyter-book
<https://github.com/executablebooks/jupyter-book>, which is a neat way to
maintain static documentation and executable jupyter notebooks from the
same source files.  The source files are written in Myst flavored markdown
<https://mystmd.org/>, so I started with a simpleminded fork of the gfm
exporter <https://github.com/titaniumbones/ox-myst>. What I'd really like,
though is something more like ox-hugo
<https://github.com/kaushalmodi/ox-hugo>, which maintains a whole blog in a
single org file.  For this to work, I need to export each individual page
of the "book" to its own markdown page.  However, jupyter-book expects to
find the title of the page in the initial first-level heading.  So I'd like
to retain the subtree "title" as a first-level heading, and demote the
remaining headings to their original state within the larger org document.

Does anyone know of an existing exporter that already does this, from which
I can steal? Or if not, how would you suggest I go about doing this?

Thanks,

Matt