Quoth Robert Pluim <rpluim@gmail.com>
on Tue, 21 Feb 2023 15:47:11 +0100:
> […]
> Everything in Emacs should be in the manual :-)

Indeed.

> […]
> Sorry, I meant "a complete sentence, and only taking up one screen
> line, not exceeding `emacs-lisp-docstring-fill-column'", ie
>
>     Whether to call the Un*x 'man' command synchronously.
>     When this is non-nil call 'man' synchronously instead of the default
>     asynchronous behaviour.
>
> since `apropos' displays only the first line

Understood.  Hopefully this updated patch (against master) is starting
to look acceptable: