remove tabindex

src/components/Definition.vue

@@ -12,7 +12,7 @@
     <ul class="compound_lists">
       <CompoundList :body="compound_list" :dictionary="dictionary" v-for="(compound_list, index) in compund_lists" :key="index" @article-click="article_link_click" />
     </ul>
-    <div :is="level < 3 ? 'ol' : 'ul'" class="sub_definitions" v-if="subdefs.length" tabindex="0">
+    <div :is="level < 3 ? 'ol' : 'ul'" class="sub_definitions" v-if="subdefs.length">
       <Definition :level="level+1" :body="subdef" v-for="(subdef, index) in subdefs"  :dictionary="dictionary" :key="index" @article-click="article_link_click" />
     </div>
   </li>