An issue with our API docs is confusing which version specific pages
correspond to because we have so many duplicates. That is especially an
issue with SEO, but also rich previews & tab titles. So, this PR adds
the version to both the `title` and `description`.
We use minor versions rather than patch versions because search engines
can be slow to update and we don't want their metadata to be
out-of-date. Likewise, we call it `(latest version)` and `(dev version)`
for this same reason.
Finally, this PR automates setting metadata for the index page whereas
before we hardcoded it.
aa8e078dcf