Move docs build scripts info from intro paragraph to the Coordinating FAQ for translations

Let's do this. Let's leave the part about where the docs are hosted and create a FAQ entry about the build scripts repo. While not harmful as is, it would be improved by moving the more specific detail about the build scripts to the FAQ.

_Originally posted by @willingc in https://github.com/python/devguide/pull/1576#discussion_r2159527165_
            