feat: diffUtil added

Author: amanjeetsingh150

DiffUtil/README.md

@@ -1,6 +1,6 @@
-# UsingRetrofit
-This is an example of Square's Retrofit purely in Kotlin.
+# DiffUtil
+This is an example of using DiffUtil CallBack to improve the updation of recycler view. DiffUtil is a utility class that can calculate the difference between two lists and output a list of update operations that converts the first list into the second one. This helps to improve the performance of your recycler view.
 
 Screenshots:
 <br><br>
-<img src="Screenshot_1512116691.png" width="250px" height="400px"/>
+<img src="diffGif.gif" width="250px" height="400px"/>