Refs #23276 -- Added missing url() in some places.

docs/ref/contrib/admin/index.txt

@@ -1456,7 +1456,7 @@ templates used by the :class:`ModelAdmin` views:
 
     Notice the wrapped view in the fifth line above::
 
-        (r'^my_view/$', self.admin_site.admin_view(self.my_view))
+        url(r'^my_view/$', self.admin_site.admin_view(self.my_view))
 
     This wrapping will protect ``self.my_view`` from unauthorized access and
     will apply the ``django.views.decorators.cache.never_cache`` decorator to
@@ -1466,7 +1466,7 @@ templates used by the :class:`ModelAdmin` views:
     performed, you can pass a ``cacheable=True`` argument to
     ``AdminSite.admin_view()``::
 
-        (r'^my_view/$', self.admin_site.admin_view(self.my_view, cacheable=True))
+        url(r'^my_view/$', self.admin_site.admin_view(self.my_view, cacheable=True))
 
 .. method:: ModelAdmin.get_form(request, obj=None, **kwargs)
 

docs/ref/contrib/formtools/form-preview.txt

@@ -77,7 +77,7 @@ How to use ``FormPreview``
 
    ...and add the following line to the appropriate model in your URLconf::
 
-       (r'^post/$', SomeModelFormPreview(SomeModelForm)),
+       url(r'^post/$', SomeModelFormPreview(SomeModelForm)),
 
    where ``SomeModelForm`` is a Form or ModelForm class for the model.
 

docs/ref/contrib/syndication.txt

@@ -217,7 +217,7 @@ The police beat feeds could be accessible via URLs like this:
 
 These can be matched with a :doc:`URLconf </topics/http/urls>` line such as::
 
-    (r'^beats/(?P<beat_id>[0-9]+)/rss/$', BeatFeed()),
+    url(r'^beats/(?P<beat_id>[0-9]+)/rss/$', BeatFeed()),
 
 Like a view, the arguments in the URL are passed to the ``get_object()``
 method along with the request object.