Update red_black_tree.py

Author: lighting9999

data_structures/binary_tree/red_black_tree.py

@@ -9,7 +9,14 @@ class RedBlackTree:
     """
     A Red-Black tree, which is a self-balancing BST (binary search
     tree).
-
+     This tree has similar performance to AVL trees, but the balancing is 
+     less strict, so it will perform faster for writing/deleting nodes 
+     and slower for reading in the average case, though, because they're 
+     both balanced binary search trees, both will get the same asymptotic 
+     performance. 
+     To read more about them, https://en.wikipedia.org/wiki/Red-black_tree 
+     Unless otherwise specified, all asymptotic runtimes are specified in 
+     terms of the size of the tree.
     Examples:
     >>> tree = RedBlackTree(0)
     >>> tree = tree.insert(8).insert(-8).insert(4).insert(12)