remove vuetifycss and materialicon -> use threeshake

@nuxt/vuetify etc...

layouts/error.vue

@@ -1,16 +1,19 @@
 <template lang='pug'>
   v-container.p-4.text-center
-    v-alert(v-if="error.statusCode === 404") ¯\_(ツ)_/¯ {{error.message}}
-    v-alert(v-else type='error') <v-icon>mdi-warning</v-icon> An error occurred: {{error.message}}
+    v-alert(v-if="error.statusCode === 404" type='error' :icon='mdiAlert') ¯\_(ツ)_/¯ {{error.message}}
+    v-alert(v-else type='error' :icon='mdiAlert') An error occurred: {{error.message}}
     nuxt-link(to='/')
       v-btn Back to home
 </template>
 
 <script>
 import { mapState } from 'vuex'
-
+import { mdiAlert } from '@mdi/js'
 export default {
   props: { error: { type: Object, default: () => ({ }) } },
+  data () {
+    return { mdiAlert }
+  },
   head () {
     return { title: `${this.settings.title} - Error` }
   },