Update README for segment tree.

Author: trekhleb

src/data-structures/tree/segment-tree/README.md

@@ -24,7 +24,9 @@ can use the precomputed value at the node. Using this
 optimisation, we can prove that only `O(log n)` minimum 
 operations are done.
 
-![Segment Tree](https://www.geeksforgeeks.org/wp-content/uploads/segment-tree1.png)
+![Min Segment Tree](https://www.geeksforgeeks.org/wp-content/uploads/RangeMinimumQuery.png)
+
+![Sum Segment Tree](https://www.geeksforgeeks.org/wp-content/uploads/segment-tree1.png)
 
 ## Application