🐛  Fixed "NaNUndefined" when inserting unordered list items (#920)
🐛  Fixed "NaNUndefined" when inserting unordered list items (#920)

closes https://github.com/TryGhost/Ghost/issues/9302

- reverts the `simplemde` bump introduced in https://github.com/TryGhost/Ghost-Admin/pull/911/, the updated version of CodeMirror appears to contain a bug or incompatibility with SimpleMDE
acburdine/Ghost-Admin,kevinansfield/Ghost-Admin,acburdine/Ghost-Admin,TryGhost/Ghost-Admin,TryGhost/Ghost-Admin,kevinansfield/Ghost-Admin