Update README.md

The addition of the description of double circular linked list

Author: devAlq

src/main/java/com/thealgorithms/datastructures/lists/README.md

@@ -23,10 +23,11 @@ The `next` variable points to the next node in the data structure and value stor
 ### File descriptions:
 
 1. `CircleLinkedList.java` : A circular linked list where next pointer of last node points to first node of linked list.
-2. `SinglyLinkedList.java` : The classic case of single links.
-3. `CountSinglyLinkedListRecursion.java`: Recursively counts the size of a list.
-4. `CreateAndDetectLoop.java` : Create and detect a loop in a linked list.
-5. `DoublyLinkedList.java` : A modification of singly linked list which has a `prev` pointer to point to the previous node.
-6. `MergeKSortedLinkedlist.java` : Merges K sorted linked list with mergesort (mergesort is also the most efficient sorting algorithm for linked list).
-7. `RandomNode.java` : Selects a random node from given linked list and diplays it.
-8. `SkipList.java` : Data Structure used for storing a sorted list of elements with help of a Linked list hierarchy that connects to subsequences of elements.
+2. `DoubleCircularLinkedList`: A circular doubly linked list is a type of linked list where each node is connected to both its previous and next nodes, and the last node links back to the first node.
+3. `SinglyLinkedList.java` : The classic case of single links.
+4. `CountSinglyLinkedListRecursion.java`: Recursively counts the size of a list.
+5. `CreateAndDetectLoop.java` : Create and detect a loop in a linked list.
+6. `DoublyLinkedList.java` : A modification of singly linked list which has a `prev` pointer to point to the previous node.
+7. `MergeKSortedLinkedlist.java` : Merges K sorted linked list with mergesort (mergesort is also the most efficient sorting algorithm for linked list).
+8. `RandomNode.java` : Selects a random node from given linked list and diplays it.
+9. `SkipList.java` : Data Structure used for storing a sorted list of elements with help of a Linked list hierarchy that connects to subsequences of elements.