Update README.md

Author: mdanics

README.md

@@ -76,9 +76,10 @@ $ cd fluttergram/
 * Push the function `getFeed` with `firebase deploy --only functions`  In the output, you'll see the getFeed URL, copy that.
 * Replace the url in the `_getFeed` function in `feed.dart` with your cloud function url from the previous step.
 
-
 _**If this does not work**  and you get the error `Error: Error parsing triggers: Cannot find module './notificationHandler'` Try following [these steps](https://github.com/mdanics/fluttergram/issues/25#issuecomment-434031430). If you are still unable to get it to work please open a new issue._
 
+_You may need to create the neccessary index by running `firebase functions:log` and then clicking the link_
+
 _**If you are getting no errors, but an empty feed** You must follow users with posts as the getFeed function only returns posts from people you follow._