I'm writing a primitive exporter for 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, so I started with a simpleminded fork of the gfm exporter. What I'd really like, though is something more like 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