[RFC PATCH] doc: add support for adding configure options as Sphinx tags

[David Bremner]

Jani Nikula <jani at nikula.org> writes:

> Add the configure options specified in $(TAGS) that equal 1 as tags on
> the Sphinx command line using the -t option. The tags may be used to
> conditionally include documentation using the Sphinx "only" directive
> [1].
>
> As an example, indicate in the documentation whether the Xapian field
> processor is likely to be available (assuming the notmuch binary was
> built in the same environment as the documentation).
>
> [1] http://www.sphinx-doc.org/en/stable/markup/misc.html#including-content-based-on-tags
>

It does seem like it could potentially help people find what optional
features are available.

A couple of observations

1) Many people read documentation on-line, even in cases where some of
   us might not think it makes sense.

2) We might eventually (per an outstanding request) provide a seperate
tarball of prebuilt docs.

Both of those suggest a need to build a "generic" version of the docs.

d