Update form/form_collections.rst

Co-authored-by: Ryan Weaver <weaverryan+github@gmail.com>

Author: ThomasLandauer

form/form_collections.rst

@@ -341,7 +341,7 @@ into new ``Tag`` objects and added to the ``tags`` property of the ``Task`` obje
 JavaScript with Stimulus
 ~~~~~~~~~~~~~~~~~~~~~~~~
 
-If you're using Stimulus, wrap everything in a ``<div>``:
+If you're using `Stimulus`_, wrap everything in a ``<div>``:
 
 .. code-block:: html+twig