chore: add appflowy_editor as appflowy's dependency

frontend/app_flowy/pubspec.yaml

@@ -39,6 +39,8 @@ dependencies:
     path: packages/flowy_infra
   appflowy_board:
     path: packages/appflowy_board
+  appflowy_editor:
+    path: packages/appflowy_editor
   flutter_quill:
     git:
       url: https://github.com/appflowy/flutter-quill.git