Create Append

Author: heba-mustafa59

Diff for: Doubly Linked Lists/Append

@@ -0,0 +1,12 @@
+  public void append (int value) {
+        Node newNode = new Node(value);
+        if(length == 0) {
+            head = newNode;
+            tail = newNode;
+        } else {
+            tail.next = newNode;
+            newNode.prev = tail;
+            tail = newNode;
+        }
+        length++;
+    }