Update README.md

Author: dosart

README.md

@@ -26,7 +26,7 @@ The project was made as part of the [Coding Interview University](https://github
 
 
 ## Spanning tree
-- Kruskal's algorithm
+- [x] [Kruskal's algorithm](https://github.com/dosart/Graph_algorithms/blob/master/graph_algorithms/algorithms/kruskal/kruskal.py)
 - Prim's algorithm
 - [x] [Disjointed set union (DSU)](https://github.com/dosart/Graph_algorithms/blob/master/graph_algorithms/data_structure/disjointed_set_union/disjointed_set_union.py)