Determine how to handle search for older online versions

Search should only return results for the site version you're viewing (e.g, 15.8).

This might not actually be possible with Google since we block older versions from indexing: https://support.google.com/programmable-search/thread/158079185/configuring-google-custom-search-to-search-a-private-site-but-not-list-the-site-publically?hl=en

How should older online versions work?

• Use DocSearch?
• Use Lunr?
• Only search within latest?