Merge pull request yosupo06#1226 from NachiaVivias/mdst_example

(graph/minimum_diameter_spanning_tree) apply example_03 in task.md

graph/minimum_diameter_spanning_tree/task.md

@@ -67,3 +67,5 @@ $X$ は最小直径全域木の直径です。$e_i$ は最小直径全域木に
 @{example.example_01}
 
 @{example.example_02}
+
+@{example.example_03}