> The only reason I like PDFs is because a related set of pages reside in a single file.
Do you need a single file to copy from one place to another, or do you just want a single thing to fetch in order to get the whole document set?
If the latter, then you could [clone the SQLite docsrc repo][1] and build it locally. This would get you a pile of files in a directory, not a single thing to copy from place to place, but it has the benefit that you can then easy update your local copy with:
$ fossil up
$ make all
[1]: https://www.sqlite.org/docsrc/