This document is background information for a series of projects I am currently (as of early 2020) working on. I am making it public in an attempt to solicit useful comments and advice on the ideas documented here; to the best of my knowledge and belief, it contains no information proprietary to either my present employer nor any other commercial, non-BSD-license-using organisation.
Markdown makes a far better standard document format for hand-editable content than HTML. Previous forays into HTML-to-Markdown conversion several years ago were frustrating due to the immaturity of both the available Markdown spec(s) and of the tools then available to do the conversion (notably, now-ancient versions of Pandoc).
Converting with Pandoc
Note that there is a maintained Ruby