docs: remove comment

docs/markdown/quickstart.en-US.md

@@ -39,7 +39,7 @@ The easiest way to use Vant is to include a CDN link in the html file, after whi
   vant.Toast('Message');
 
   // Register Lazyload directive
-  // app.use(vant.Lazyload);
+  app.use(vant.Lazyload);
 </script>
 ```
 

docs/markdown/quickstart.zh-CN.md

@@ -46,7 +46,7 @@ npm i vant@next -S
 
   // 通过 CDN 引入时不会自动注册 Lazyload 组件
   // 可以通过下面的方式手动注册
-  // app.use(vant.Lazyload);
+  app.use(vant.Lazyload);
 </script>
 ```