DOC: Update edit mode tutorial

src/doc/tutorials/edit_mode.rst

@@ -75,6 +75,26 @@ to the corresponding area at the bottom of the Record. Properties and
 parents can be removed from the entity by clicking on the trash-can
 symbol. Note that a Record must always have at least one parent.
 
+From LinkAhead WebUI version 0.15, the default behavior for changing
+the values of reference properties has changed in that the dropdown
+menus to select possible values are not filled automatically for
+`performance reasons
+<https://gitlab.com/linkahead/linkahead-webui/-/issues/262>`_. Instead,
+you have to click on the pencil symbol to the right of the property
+you want to edit:
+
+.. image:: edit-lazy-load-dropdown.png
+   :width: 720
+   :alt: Clicking on the pencil symbol enables the editing of the
+         reference property.
+
+.. note::
+
+   The behavior of version 0.14.x and before, i.e., enable and load
+   all reference dropdowns immediatly after starting to edit the
+   entity, can be restored by starting LinkAhead with the
+   ``BUILD_EDIT_MODE_LAZY_DROPDOWN_LOADING = DISABLED`` option.
+
 When many Entities are valid candidates for a reference property not all
 might be available in the drop down element. In those cases, the drop down
 warns, that only a subset is shown and a new button with a pencil symbol is