This is a follow up of DOCU-1063.

1063 has tackled the bigger changes, however, there are still some minor adaptations and improvements ongoing.
Check this epic "Content Editor fine-tuning" epic

Things we already know:

• Stories app
  • Check screenshots
  • Check "Outline" section (has already slightly changed again)
• Developing a custom content editor
  • updates (in code) following the latest recomandations concerning actions
• Developing and rendering custom content blocks
  • Fully qualified class name of the block definition class has changed!
  • See pull request
• Content editor
  • few minor changes ...

etc. (add more stuff as soon as it known)