Add explanation split infinitive

src/components/Header.vue

@@ -9,7 +9,7 @@
     <span v-if="split_inf" tabindex="0"> (kløyvd infinitiv: <i>-a</i>
       <v-menu rounded="0" v-model="menu" offset-x max-width="200px">
         <template v-slot:activator="{ on, attrs }">
-          <v-btn x-small icon v-on="on" v-bind="attrs" class="info-button">
+          <v-btn aria-label="Mer informasjon om kløyvd infinitiv" x-small icon v-on="on" v-bind="attrs" class="info-button">
             <v-icon color="primary" size="14px">$vuetify.icons.value.info</v-icon>
           </v-btn>
         </template>