add pwa app

layouts/pwa.vue

@@ -0,0 +1,39 @@
+<template>
+  <div class="pwa" :class="darkMode ? 'dark-mode' : null">
+    <div class="connection-status" v-if="$nuxt.isOffline">
+      <p>{{ staticData.connection }}</p>
+    </div>
+    <pwa-about/>
+    <pwa-header @darkModeStatus="changeTheme"/>
+    <nuxt/>
+    <page-load/>
+  </div>
+</template>
+
+
+<script>
+export default {
+  data() {
+    return {
+      darkMode: false
+    }
+  },
+  computed: {
+    staticData() {
+      return this.$store.state.staticData.pwa[this.$route.params.lang]
+    }
+  },
+  methods: {
+    changeTheme(val) {
+      this.darkMode = val
+    }
+  },
+  head() {
+    return {
+      htmlAttrs: {
+        lang: this.$route.params.lang
+      }
+    }
+  }
+}
+</script>