The user management docs are now one page, because the division between
accounts and aliases is useless because there simply isn't enough
content to justify the split. I improved and updated the text a bit.
* docs: change some absolute links to relative links
* docs: change most hard-coded links to `edge` to point to `latest`
* Apply suggestions from code review
* docs: revert 404 page to edge and change canonical link to `latest
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Co-authored-by: Brennan Kinney <5098581+polarathene@users.noreply.github.com>
Co-authored-by: Georg Lauterbach <44545919+georglauterbach@users.noreply.github.com>
