docs: 添加页面访问统计图表

README.md

@@ -159,6 +159,8 @@ $ npm test
 
 ## Stargazers over time
 
+[![Flag Counter](https://s05.flagcounter.com/count2/uCWd/bg_FFFFFF/txt_000000/border_CCCCCC/columns_8/maxflags_24/viewers_0/labels_1/pageviews_1/flags_0/percent_0/)](https://info.flagcounter.com/uCWd)
+
 [![Stargazers over time](https://starcharts.herokuapp.com/modood/Administrative-divisions-of-China.svg)](https://starcharts.herokuapp.com/modood/Administrative-divisions-of-China)
 
 ## Contributing