chore: move files to frontend

frontend/src/App.vue

@@ -0,0 +1,23 @@
+<template>
+  <div>
+    <router-view></router-view>
+  </div>
+</template>
+
+<script>
+export default {
+  name: 'app',
+  mounted () {
+    const loading = document.getElementById('loading')
+    loading.classList.add('done')
+
+    setTimeout(function () {
+      loading.parentNode.removeChild(loading)
+    }, 200)
+  }
+}
+</script>
+
+<style>
+@import './css/styles.css';
+</style>