doc: add navigation as a component

src/App.vue

@@ -1,11 +1,16 @@
 <template>
   <div>
+    <Navigation />
     <router-view />
   </div>
 </template>
 
 <script>
+import Navigation from "./components/Navigation.vue";
 export default {
+  components: {
+    Navigation,
+  },
   setup() {
     // Create data / vars