Document isDraggedOver

docs/guide/index.md

@@ -77,6 +77,10 @@ disabledFields: [
 ];
 ```
 
+To highlight, which fields are disabled, the `disabledField` slot can be used. It receives the slot prop `isDraggedOver`,
+which is a boolean indicating whether something is currently dragged over the grid. This can be used to only show the
+disabled fields when something is dragging. An example for this can be found in Example number 7.
+
 ## Prevent items from being dragged
 
 To disable dragging of a specific item, simply set the attribute `disabled` of the item to `true`.