The syntax of readonly markup appears to have changed at some point. Now instead of {"insert":{"readonly":"Some readonly text\n"}} it wants {"attributes":{"readonly":true},"insert":"Some readonly text\n"}
Note that this change breaks the demo.
The syntax of readonly markup appears to have changed at some point. Now instead of {"insert":{"readonly":"Some readonly text\n"}} it wants {"attributes":{"readonly":true},"insert":"Some readonly text\n"}
Note that this change breaks the demo.