Add Wiki Link for Splay Tree Implementation in Binary Tree

Signed-off-by: Arya Pratap Singh <notaryasingh@gmail.com>

Author: ARYPROGRAMMER

data_structures/binary_tree/splay_tree.py

@@ -8,6 +8,8 @@
 The splaying operation moves a node to the root by performing a series of
 rotations, making frequently accessed elements faster to access in the future.
 
+For more information, see: https://en.wikipedia.org/wiki/Splay_tree
+
 Time Complexity (amortized):
 - Search: O(log n)
 - Insert: O(log n)