Fix HTML validation warnings in website

[vladlen]

Summary

<img> and <hr> tags fixed in templates.
Obsolete name="""" removed from <a> tags in templates.

PR: 297509

[ziaee]

website/themes/beastie/layouts/_partials/advisories.html

18

I already started vibecoding script to do this, but there's a lot of different ones everywhere. So far I've found <hr />, <br />, <col /> and <img ... />.

[ziaee]

Also a commit message title for this should really be something like "website: Convert XHTML to HTML" in accordance with guidelines here: https://docs.freebsd.org/en/articles/committers-guide/#port-commit-message-formats

[vladlen]

In D60579#1389082, @ziaee wrote:

Also a commit message title for this should really be something like "website: Convert XHTML to HTML" in accordance with guidelines here: https://docs.freebsd.org/en/articles/committers-guide/#port-commit-message-formats

I used the title from the first commit message in PR: 297509 to join all commits under one name.

This patch is the first, that fix warnings, I will change title.

[vladlen]

website/themes/beastie/layouts/_partials/advisories.html

18

Really the biggest parts of the warnings will be fixed by this patch, and I am preparing the patch for the footer.

I think, the remaining of the warnings need to be fixed in hugo or AsciiDoctor - I wrote examples today in PR 297509 - it is much harder, I do not have idea, how to fix them (options? macros?).

[carlavilla]

For the HTML5, in theory, if you don't tell anything to AsciiDoctor, the software is going to use HTML5 by default.
https://docs.asciidoctor.org/asciidoctor/latest/convert/available/

Make the commit, we can wait the runners to deploy it in PRO and check it later