Include head vue into tab order

src/App.vue

 <template>
   <v-app id="app">
     <header>
-    <div class="about-link"><router-link to="/om">OM ORDBØKENE</router-link></div>
-      <h1><a :class="$vuetify.breakpoint.name" href="/">Ordbøkene</a></h1>
+    <div class="about-link"><router-link to="/om" tabindex="2">OM ORDBØKENE</router-link></div>
+      <h1><a :class="$vuetify.breakpoint.name" href="/" tabindex="1">Ordbøkene</a></h1>
       <div class="beta" :title="release">{{version_label}}</div>
-      <p class="sub-title"><router-link to="/">Bokmålsordboka og Nynorskordboka</router-link></p>
+      <p class="sub-title"><router-link to="/" tabindex="3">Bokmålsordboka og Nynorskordboka</router-link></p>
     </header>
     <router-view></router-view>
     <footer>