Fixes#13240. It's not really better than source-code comments it replaced,
but it's in a better accessible place.
(cherry picked from commit e3da83297f)
There's no change in content except for amending the title of the
section to mention "frameworks", as e.g. I don't consider Qt a language,
and it's likely there will be more of similar cases in future.
To be certain, I checked diff of the generated HTMLs.
