Update README.md

Author: AvinandanBose

README.md

@@ -1549,6 +1549,8 @@ Creates an empty enum set with the specified element type.
   <li> <h3> The ConcurrentSkipListSet  does not allow null elements, because null arguments and return values cannot be reliably distinguished from the absence of elements. </h3> </li>
   <li> <h3> The ConcurrentSkipListSet is thread-safe. </h3> </li>
 
+
+<h2> </h2>
  <h2 align= "center" > The ConcurrentSkipListSet Methods :  </h2>