blacken-docs: Adds commas at the end to make it look identical to pre-black version

Author: jvzammit

docs/api-guide/caching.md

@@ -31,28 +31,31 @@ class UserViewSet(viewsets.ViewSet):
     @method_decorator(cache_page(60 * 60 * 2))
     @method_decorator(vary_on_cookie)
     def list(self, request, format=None):
-        content = {"user_feed": request.user.get_user_feed()}
+        content = {
+            "user_feed": request.user.get_user_feed(),
+        }
         return Response(content)
 
 
 class ProfileView(APIView):
     # With auth: cache requested url for each user for 2 hours
     @method_decorator(cache_page(60 * 60 * 2))
-    @method_decorator(
-        vary_on_headers(
-            "Authorization",
-        )
-    )
+    @method_decorator(vary_on_headers("Authorization"))
     def get(self, request, format=None):
-        content = {"user_feed": request.user.get_user_feed()}
+        content = {
+            "user_feed": request.user.get_user_feed(),
+        }
         return Response(content)
 
 
 class PostView(APIView):
     # Cache page for the requested url
     @method_decorator(cache_page(60 * 60 * 2))
     def get(self, request, format=None):
-        content = {"title": "Post title", "body": "Post content"}
+        content = {
+            "title": "Post title",
+            "body": "Post content",
+        }
         return Response(content)
 ```