[Doc] update vant-demo respo (#318)

* fix: Tabbar icon line-height

* [new feature] progress add showPivot prop

* [new feature] TabItem support vue-router

* [new feature] update document header style

* [Doc] add toast english ducoment

* [bugfix] Search box-sizing wrong

* [Doc] update vant-demo respo

README.zh-CN.md

@@ -104,7 +104,7 @@ Vue.use(Vant);
 - [更新日志](https://www.youzanyun.com/zanui/vant#/en-US/component/changelog)
 - [React 组件库 Zent](https://www.youzanyun.com/zanui/zent)
 - [vue-cli-template-vant](https://github.com/youzan/vue-cli-template-vant) 
-- [vant-demo](https://github.com/chenjiahan/vant-demo)
+- [vant-demo](https://github.com/youzan/vant-demo)
  
 ## 开源协议