renew README

Author: linjing-lab

README.md

@@ -64,7 +64,7 @@ I test the performance of the sorting algorithm after adding the keyword sorting
 
 The design of reverse sorting of all methods is completely correct, and the design of keyword sorting based on bubble sorting optimized is feasible, which is consistent with the usage of *sorted* parameter officially released by Python.
 
-The examples of keyword sorting are underlying:
+The example of keyword sorting are underlying:
 
 ```python
 data = [('Alex', 100, 90, 98, 95), ('Jack', 97, 89, 92, 99), ('Peter', 92, 95, 92, 96), ('Li', 97, 88, 98, 92)]