[m-rev.] for post-commit review: consistent file names for manuals

[Julien Fischer]

On Mon, 11 Aug 2025 at 15:47, Zoltan Somogyi <zoltan.somogyi at runbox.com> wrote:

> Use consistent file-names in the doc directory.

...

> doc/Mmakefile:
>     Rename files in variable definitions, target lists, source lists, actions,
>     and comments.

It's probably worth adding a comment somewhere in this Mmakefile, that changes
to the filenames need to also be reflected on the website. (I have done so
for this change.)

>
>     Replace blocks of file-name-specific rules with a single generic rule
>     where the uniformity of names makes this possible.
>
>     Start builtin pdf files by default, since the motivation for this change
>     is fixing an inconsistency between .html and .pdf versions of the same
>     manual.

Building the PDFs by default breaks source distribution installation on
testing.mercurylang.org because it does not appear to have tools necessary
to build the PDFs installed.  Arguably, this is an existing bug because the
target that builds the pdfs should do nothing unless the appopriate tools
*are* installed.

Julien.