I was quite unhappy with shape of our documentation for some time, but this week I finally found some time to dig deeper into conversion into something more usable.
Nowadays I'm mostly using Sphinx for writing documentation, which allows to easily write using RST and provides output to various formats. Together with Read the Docs service, it makes great combo for providing user documentation, which I use for example for Weblate.
So with a little bit of magic in Python and Beautiful Soup I was able to convert most of the HTML documentation into RST without tons of manual work. The resulting source (and ugly conversion script) temporarily lives on my github and generated documentation is available on Read the Docs.
There are of course still many things to improve, but I think even right now it is easier to navigate than previous monolithic HTML file.
Now we need to decide if and how to integrate this into official repositories and I can then continue on improving the documentation content.