Revert Sphinx documentation [Was: Issues with Sphinx]

[Gerald Pfeifer]

On Mon, 14 Nov 2022, Jonathan Wakely wrote:
> I formatted my new region/endregion pragmas on one line because that
> seemed to be how it should be done for rSt, e.g. we had:
> 
> ``#pragma GCC push_options`` ``#pragma GCC pop_options``
> 
> But I think the attached patch is more correct for how we document
> pragmas in texinfo.
> 
> OK for trunk?

Looks good to my eyes. Thank you for caring for such details, Jonathan!

Gerald