fixed 20665172 from https://gitee.com/ge-yafang/docs/pulls/11171

update zh-cn/application-dev/quick-start/start-with-ets-stage.md.
Signed-off-by: N葛亚芳 <geyafang@huawei.com>

zh-cn/application-dev/quick-start/start-with-ets-stage.md

@@ -189,6 +189,7 @@
    
    ```ts
    // index.ets
+   // 导入页面路由模块
    import router from '@ohos.router';
    
    @Entry
@@ -233,6 +234,7 @@
    
    ```ts
    // second.ets
+   // 导入页面路由模块
    import router from '@ohos.router';
    
    @Entry