Because Next is not letting us use periods in the locales, this diff implements custom versioning. This is for the best anyway, because using internationalization for versioning was very much a hack and we don't know how it can break down the line.
Not using internationalization anymore
Since we are doing custom versioning now, we can't use the _apidocs/[...page].tsx file separately, because routes like /0.9.19/_apidocs/abc would not match. Therefore, we have this catchall route take care of _everything_ and render data appropriately.
This file has all the magic. It implements a hook (which is a wrapper around useRouter) that allows us to extract the version page and return the rest of the path to use in other parts of the site.