Great! Can you also make the script available to generate this? I’m happy to include that in the source distribution, so anyone can roll their own copy at any time that reflects precisely their version.
I have described the process which uses a tool written in go, so not a simple script unfortunately. The dashing.json file in this repo contains the CSS selectors I used. I plan to update this whenever a new devel version is released, but it’s easy enough to build for other versions.
Nice to have this. Pity it is not in Prolog 
There is a lot of HTML processing there and helpt/1 and friends already contain all the logic to index and segment the manual. You can access sqlite both through ODBC and the sqlite driver pack by Nicos …
‘read_line_to_string/2’ is not showing up in the zeal docs, there is probably some bug in the script.
That’s because in my installation it’s not in the readutil.html file. It is also not in man/lib/readutil.doc so the homepage does something extra to find the docs for this. Another example is concurrent_maplist/2. Not sure what to do here… I’ll wait some before pushing this upstream, maybe someone knows something.
Redoing it with Prolog would be a nice excercise but also more work 
Some libraries are not part of the HTML files and the website generates the help directly from the PlDoc comments in the (loaded) library. Zeal will have the same limitations as help/1 from the toplevel. For some outdated libraries this is ok, but eventually all well maintained libraries should be moved to the HTML docs. That is not really hard. See man/lib in the sources.
Would probably have been less work. help/1 and apropos/1 maintain an index of the documented predicates and there is a call to get the HTML for a specific predicate. So, generating an HTML document for every documented predicate is about 2 lines 