minor tweak to doc

docs/usage.rst

@@ -17,16 +17,15 @@ Using the template tag
 ----------------------
 
 There is also a template tag you can use outside of a streamfield, within a page.
-
 All this is doing is rendering the form using the same block as in the streamfield.
 
 The tag takes three parameters:
 
-* **slug**: The ``slug`` of the form.
-* **reference**: This should be a unique string and needs to be persistent on refresh/reload. See note below.
-* **action**: The form action url.
+* **slug** (``string``) - The slug of the form instance.
+* **reference** (``string``) - This should be a unique string and needs to be persistent on refresh/reload. See note below.
+* **action** (``string``) optional - The form action url.
 
-.. warning:: The reference is used when the form is being validated.
+.. note:: The reference is used when the form is being validated.
 
     Because you can have any number of the same form on a page there needs to be a way of uniquely identifying the form beyond its ``PK``.
     This is so that when the form has validation errors and it is passed back through the pages context, We know what form it is.