Create duplicate

[erlend-sh]

Missing the option to create a copy of a doc, for alternate-path explorations and such.

This is also a handy workaround for the currently lacking privilege-revocations. As far as I know there's currenly no way for me to revoke edit privileges, since they're baked into to the URL i shared. That's less of a problem if I can easily re-start the document with a duplicate.

[bschlagel]

Thanks yes agree I'd like to get this one in as well! We previously had a 'templates' feature that we removed to simplify things; I think "duplicate" would be a nice simpler replacement for that functionality as well as a lightweight way to fork or make backups.

(Separately I think we should add a way to refresh token for edit link too, both useful)