[Doc-SIG] Moving language and version switchers out of cpython

[Julien Palard]

Hi doc-sig and release managers,

I'd like the simplify the maintenance of the language and version 
switchers of docs.python.org.

The current implementation lies in cpython's 
Doc/tools/static/switchers.js, witch contains a hardcoded list of 
languages and versions (that has to be updated on each new release and 
each new language, and backported in multiple branches).

It can be enhanced by a clearer separation:

- cpython Doc/ would build a simple standalone documentation, without 
switchers.
- docsbuild-script would be responsible to add the switchers.


Pro: We do no longer need to keep an up-to-date list of languages and 
version in all cpython branches, a single commit in docsbuild-scripts 
would update all switchers.

Con: Maybe, somewhere, someone is building a private version of 
docs.python.org, without docsbuild-script, and will be sad to see the 
switchers disapear. The probablility is low as they would have to have 
the same URLs as us (/{language}/{version}/), the same languages, and 
the same versions build, as all is imposed by switchers.js.

I opened an issue [1] and a draft PR [2] to experiment around the idea, 
there's still some work to do, but I have to sleep.

What do you think?

[1]: https://github.com/python/docsbuild-scripts/issues/90
[2]: https://github.com/python/docsbuild-scripts/pull/91
-- 
[Julien Palard](https://mdk.fr)