Update README.md

Author: harjot-oberai

README.md

@@ -1,5 +1,9 @@
 # Croller
-A circular seekbar for Android, with a control knob! (for the lack of a better  word).
+<img src = "https://github.com/harjot-oberai/Croller/blob/master/screens/screen2.jpg" width = "150">
+<img src = "https://github.com/harjot-oberai/Croller/blob/master/screens/screen1.jpg" width = "150">
+<img src = "https://github.com/harjot-oberai/Croller/blob/master/screens/screen3.jpg" width = "150">
+<img src = "https://github.com/harjot-oberai/Croller/blob/master/screens/screen4.jpg" width = "150"><br>
+#### A circular seekbar for Android, with a control knob! (for the lack of a better  word).
 
 # Usage
 The library is currently not uploaded to jCenter, so to use it, follow these steps