Add Better Developer Docs Around Doc Site Functionality and Strategy

[KetanReddy]

Inspired by this. Its definitely not super obvious how the doc site repository works, what the different site versions correlate to, and how changes are deployed there. We should flesh out this section in the newCONTRIBUTORS.md or CONTRIBUTORS.md file as well as on the doc site itself.

[kharrop]

Added a section around this as part of this PR #660