Collaboration support
Add collaborative editing through Changesets as implemented in EtherPad
https://github.com/ether/etherpad-lite/blob/develop/doc/api/changeset_library.md
https://github.com/ether/etherpad-lite/blob/develop/src/static/js/Changeset.js
https://github.com/0xTheProDev/Operational-Transformation
https://github.com/ottypes/json0
https://github.com/kbadk/json0-ot-diff
https://github.com/Operational-Transformation/ot.js (unmaintained)