Update README.md

Added endpoint and credit Spotify

Author: CoderJava

README.md

@@ -1,5 +1,5 @@
 # Flutter Backend Driven UI
-
+### Introduction
 Backend Driven UI is a concept for build UI with flexible pages from
 backend. So, your backend should return a JSON response with containing
 UI property and your app will convert it to UI.
@@ -11,3 +11,6 @@ https://bengkelrobot.net:8003/api/dynamic-widget/home-page
 
 ![Screenshot](https://raw.githubusercontent.com/CoderJava/Flutter-Backend-Driven-UI/master/screenshots/screenshot_1.png
 "Screenshot")
+
+### Assets And Images
+[Spotify API](https://developer.spotify.com/)