add functionality to about-button

src/App.vue

@@ -10,7 +10,8 @@
       <v-divider vertical/>
       <v-btn text><v-icon left>settings</v-icon>Instillinger<v-icon right>expand_more</v-icon></v-btn>
             <v-divider vertical/>
-      <v-btn text><v-icon left>info</v-icon>Om ordbøkene</v-btn>
+      <v-btn text @click="toggleAbout"><v-icon left>{{$route.name=='about'? "chevron_left":"info"}}</v-icon>{{$route.name=='about'? "Tilbake":"Om ordbøkene"}}</v-btn>
+
       </v-toolbar-items>
       <v-toolbar-items class="hidden-md-and-up">
       <v-divider vertical/>
@@ -45,6 +46,11 @@
         release: process.env.VUE_APP_RELEASE
       }
     },
+    methods: {
+      toggleAbout: function() {
+        this.$route.name=='about'? this.$router.back(): this.$router.push('/om')
+      }
+    },
     mounted: function(){
       document.title = 'Ordbøkene - ' + this.version_label
     }