Update README.md

Author: LyangHiga

data-structures/graph/README.md

@@ -3,8 +3,10 @@
 - BFS
   - [BFS' lectures](https://www.coursera.org/learn/algorithms-graphs-data-structures/lecture/JZRXz/breadth-first-search-bfs-the-basics)
   - [Algorithm Design 1st Edition](https://www.amazon.com/Algorithm-Design-Jon-Kleinberg/dp/0321295358)
-- Undirected connectivity - [BFS and Undirected Connectivity - Lecture
-  ](https://www.coursera.org/learn/algorithms-graphs-data-structures/lecture/BTVWn/bfs-and-undirected-connectivity) - [Algorithm Design 1st Edition](https://www.amazon.com/Algorithm-Design-Jon-Kleinberg/dp/0321295358)
+- Undirected connectivity 
+  - [BFS and Undirected Connectivity - Lecture
+  ](https://www.coursera.org/learn/algorithms-graphs-data-structures/lecture/BTVWn/bfs-and-undirected-connectivity) 
+  - [Algorithm Design 1st Edition](https://www.amazon.com/Algorithm-Design-Jon-Kleinberg/dp/0321295358)
 - DFS
   - [DFS' lectures](https://www.coursera.org/learn/algorithms-graphs-data-structures/lecture/pKr0Y/depth-first-search-dfs-the-basics)
   - [Algorithm Design 1st Edition](https://www.amazon.com/Algorithm-Design-Jon-Kleinberg/dp/0321295358)