build: add files of vant-cli 2

packages/vant-cli/site/mobile/App.vue

@@ -0,0 +1,34 @@
+<template>
+  <div>
+    <nav-bar />
+    <keep-alive>
+      <router-view />
+    </keep-alive>
+  </div>
+</template>
+
+<script>
+import DemoNav from './components/DemoNav';
+
+export default {
+  components: {
+    DemoNav
+  }
+};
+</script>
+
+<style lang="less">
+body {
+  min-width: 100vw;
+  color: #323233;
+  font-family: 'PingFang SC', Helvetica, Tohoma, Arial, sans-serif;
+  line-height: 1;
+  background-color: #f8f8f8;
+  -webkit-font-smoothing: antialiased;
+}
+
+::-webkit-scrollbar {
+  width: 0;
+  background: transparent;
+}
+</style>