Update promises.js

Added fetch notes reference.

Author: aayushyadavz

10_Advance/promises.js

@@ -104,4 +104,6 @@ fetch('https://api.github.com/users/AayushYadavz')
     return response.json()
 })
 .then((data) => {console.log(data);})
-.catch((err) => {console.log(err);})
+.catch((err) => {console.log(err);})
+
+//------------------------------- Fetch Notes & Diagram is in readme.md ---------------