Avoid broken links for file renames/deletes in Sawtooth doc

Research, scope, and implement a way to avoid broken links when changing file names and internal links (section title) in updated/reorganized doc content.  For example, if a doc file is renamed (when the title changes) or deleted, anyone who bookmarked that topic should not get a broken link. Instead, they should be redirected to the replacement file or next best option in the doc (which could be the intro/contents page).

This task requires technical help from someone who understands how sawtooth.hyperledger.org/docs is set up.