Automate locale selection for documentation pages

[AustinShalit]

Hi folks,

@agjohnson mentioned in #4600 that RTD was looking into redirecting users to a translation that matches their browser's language.

User requested /, redirect to /<default language>/<version> if no accept language header, or /<accept language header code>/<version> if there is a header. This change is relatively easy and we have an issue already tracking this internally.

I was just looking to see what happened with that suggestion.

Thank you,
Austin

[agjohnson]

I'd still like to see this happen, and we're probably more equipped for this now that we have an application in front of all requests that serve documentation. I'm not sure what priority we have on this though, we'd probably want to get up to date figures on how many projects have active translations.

[humitos]

I renamed the issue to something similar to #8709 which is related, but for dashboard instead of documentation pages.

[humitos]

Today I saw python/docsbuild-scripts#82 (comment) and I wanted to link it here as a reference.