grammar fix in readme

Author: ikesnowy

README.md

@@ -20,7 +20,7 @@
   - [2.2 归并排序 Mergesort](https://github.com/ikesnowy/Algorithms-4th-Edition-in-Csharp/tree/master/2%20Sorting/2.2)
   - [2.3 快速排序 Quicksort](https://github.com/ikesnowy/Algorithms-4th-Edition-in-Csharp/tree/master/2%20Sorting/2.3)
   - [2.4 优先队列 Priority Queues](https://github.com/ikesnowy/Algorithms-4th-Edition-in-Csharp/tree/master/2%20Sorting/2.4)
-  - [2.5 应用 Sort Applications](https://github.com/ikesnowy/Algorithms-4th-Edition-in-Csharp/tree/master/2%20Sorting/2.5)
+  - [2.5 应用 Sorting Applications](https://github.com/ikesnowy/Algorithms-4th-Edition-in-Csharp/tree/master/2%20Sorting/2.5)
 
 
 ## 使用方法 & 开发环境