bug#73425: 31.0.50; Support images in HTML versions of ELPA package manuals

[Stefan Monnier]

> AFAICT, the plan is as follows:
>
> - Add support in package specs for "associated files" for each of the
>   manuals (ideally also for the `:readme`, BTW).

OK, I added a `:doc-files` thingy.
Currently it can be a list of file or dir names, and if it's a dir we
copy all the files in it (but not recursively).

> - Arrange to copy those "associated files" to the `doc/<PACKAGE>/`
>   subdirectory of the `archive(-devel)/` area.

Done.

> - Massage the HTML files so that `href="snapshot.png"` becomes
>   `href="<PACKAGE>/snapshot.png"`.  For the `:readme` case, we should
>   instead redirect them to `doc/<PACKAGE>/snapshot.png`.

Done to some extent but I'm not completely sure what to do with the
Kubed manual (and I haven't looked at the `:readme` case at all).

Eshel: could you explain to me the "/assets" thingy in the references
to images in the Texi (and resulting HTML)?

> This should make the HTML links to images work in the web versions of
> the manuals.

And indeed it seems to work for Hyerpbole.
Mats&Robert: please check http://elpa.gnu.org/devel/doc/hyperbole.html

> - Offer a way to specify part of the package specs directly in the
>   package itself (presumably within the pseudo-headers of the main
>   file).  Would be useful in general rather than just for "associated
>   files".

Not there yet.

> - Maybe also offer some support to generate the list of associated files
>   dynamically/automatically by scrubbing the generated HTML files?

Even less there yet.

> - Make sure the links to associated files work also for the Info
>   versions of the manuals, even when they're moved to the
>   root directory.

Not there yet either.


        Stefan