bug#68824: treesitter support for outline-minor-mode

[Juri Linkov]

>> >> +@vindex outline-search-function
>> >> +  Instead of setting the variable @code{outline-regexp}, you can set
>> >> +the variable @code{outline-search-function} to a function that
>> >> +matches the current heading and searches for the next one.
>> >
>> > This should tell which arguments will be passed to the function, and
>> > what it is expected to do and return.
>>
>> This is the Emacs User Manual, not the Emacs Lisp Reference Manual.
>> Are you sure that arguments should be described here?
>
> Sorry, I wasn't aware that was for the user manual.  But why are such
> variables documented in the user manual to begin with? why not in the
> ELisp manual?

The problem is that the Info node in the ELisp manual would be too small.
I have no idea what to write in that node more than 10 lines from the
docstring of 'outline-search-function'.