Fixed headline.

Author: Simon Prickett

README.md

@@ -132,6 +132,6 @@ To run the linter:
 npm run lint
 ```
 
-### Subscribe to our YouTube Channel
+# Subscribe to our YouTube Channel
 
 We'd love for you to [check out our YouTube channel](https://youtube.com/redislabs), and subscribe if you want to see more Redis videos!