Add a https://tails.boum.org/$relative_path rel=canonical tag to our website to prevent confusions
As our website is easily compiled and can be hosted in other places (after changing their content), if those places are indexed by search engines it could lead to many issues.
We have seen this problem happening specifically with our staging website, as reported at sysadmin#17747 (moved). We need to add some change on that specific instance, but we should also add a rel=canonical tag to our page template, so the search engines also prioritise our URL when the website is published elsewhere.
I had a look onto the template, but it is not clear for me how to make the tag construct the URL.
the result should differ from page to page, and show the same content when compiled. i.e. https://tails.boum.org/about/index.it.html and https://staging.tails.boum.org/about/index.it.html should show the same URL:
<link rel="canonical" href="https://tails.boum.org/about/index.it.html" />
I see most of the URLs on the template are relative, so I don't know how to create that URL.