SEO enhancements / requests

[MiloCasagrande]

We've been asked to look into some SEO enhancements after a few crawls of our websites have been performed and SEO-related issues have been detected.

I tried to look into solving some of those, but I have no idea how to achieve that with Sphinx (or if it's even possible).

The issues we should try to fix are:

• Missing canonical link in each page
  Pages like this can also be accessed and indexed without the trailing index.html (here) and should contain a canonical link (ideally to the one without the index.html) or search engines will consider the content as duplicate, and index it twice. I looked into Sphinx docs, but could not find an easy solution without having to hack the Sphinx theme.
• Missing publisher, author, datePublished (and possibly others) tags in each page
  I'm not even sure if we can or want to fix those. These are parts of what Google call structured data and results in higher page rankings, better search results etc.... I know what needs to be added to the pages, I have no idea how to achieve that with Sphinx.

[MiloCasagrande]

@MatthewCroughan I'm assigning this to you since you probably hacked the most the docs and Sphinx, so any inputs/insights is welcome.

[MatthewCroughan]

I believe this is the right config option for our theme. Though if we were ever to change the theme, we'd have to re-investigate this option. It's interesting that the theme has control over how the canonical url is presented. A mistake in the architecture of Sphinx probably. I will look into this after I have solved the higher priority tasks.

https://sphinx-rtd-theme.readthedocs.io/en/stable/configuring.html#confval-canonical_url

[MiloCasagrande]

https://sphinx-rtd-theme.readthedocs.io/en/stable/configuring.html#confval-canonical_url

Yeah, that was my finding as well, but as far as I understood that setting only works for the root url (the homepage), and we need it for all pages.

[MatthewCroughan]

For as long as we use the RTD theme, I do not think structured data is possible today.

readthedocs/readthedocs.org#5208

[MatthewCroughan]

This should be fixed by a8eabcd

This comment turned out to be correct. #137 (comment)

As can be seen by a grep, each page now has a unique canonical url that points to index.html, which I believe is what we want:

matthew@thinkpad ~/git/foundries/docs/build/html (improvements-05) $ grep -r '<link rel="canonical"'
reference-manual/factory/fioctl/fioctl.html:    <link rel="canonical" href="https://docs.foundries.io/reference-manual/factory/fioctl/fioctl.html"/>
reference-manual/factory/fioctl/index.html:    <link rel="canonical" href="https://docs.foundries.io/reference-manual/factory/fioctl/index.html"/>
reference-manual/factory/factory-sources.html:    <link rel="canonical" href="https://docs.foundries.io/reference-manual/factory/factory-sources.html"/>
reference-manual/factory/api-access.html:    <link rel="canonical" href="https://docs.foundries.io/reference-manual/factory/api-access.html"/>
reference-manual/factory/factory-definition.html:    <link rel="canonical" href="https://docs.foundries.io/reference-manual/factory/factory-definition.html"/>
reference-manual/factory/factory.html:    <link rel="canonical" href="https://docs.foundries.io/reference-manual/factory/factory.html"/>
reference-manual/linux/linux-update.html:    <link rel="canonical" href="https://docs.foundries.io/reference-manual/linux/linux-update.html"/>