feat: Upgrade editor (#1227)

* WIP

* document migration

* fix: Handle clashing keyboard events

* fix: convert getSummary

* fix: parseDocumentIds

* lint

* fix: Remove unused plugin

* Move editor version to header
Add editor version check for API endpoints

* fix: Editor update auto-reload
Bump RME

* test

* bump rme

* Remove slate flow types, improve themeing, bump rme

* bump rme

* fix: parseDocumentIds returning duplicate ID's, improved regression tests

* test

* fix: Missing code styles

* lint

* chore: Upgrade v2 migration to use AST

* Bump RME

* Update welcome doc

* add highlight to keyboard shortcuts ref

* theming improvements

* fix: Code comments show as headings, closes #1255

* loop

* fix: TOC highlighting

* lint

* add: Automated backup of docs before migration

* Update embeds to new format

* fix: React warning

* bump to final editor version 10.0.0

* test

.flowconfig

@@ -9,10 +9,6 @@
 .*/node_modules/polished/.*
 .*/node_modules/react-side-effect/.*
 .*/node_modules/fbjs/.*
-.*/node_modules/slate-edit-code/example/.*
-.*/node_modules/slate-edit-code/lib/.*
-.*/node_modules/slate-edit-list/.*
-.*/node_modules/slate-prism/.*
 .*/node_modules/config-chain/.*
 .*/server/scripts/.*
 *.test.js