Add Spanish language to dropdown (#2353)

Author: Vergara92

themes/vue/layout/layout.ejs

@@ -16,6 +16,7 @@
     <link rel="alternate" hreflang="ko" href="https://kr.vuejs.org/<%- page.path %>">
     <link rel="alternate" hreflang="pt-BR" href="https://br.vuejs.org/<%- page.path %>">
     <link rel="alternate" hreflang="fr" href="https://fr.vuejs.org/<%- page.path %>">
+    <link rel="alternate" hreflang="es" href="https://es.vuejs.org/<%- page.path %>">
 
     <meta property="og:type" content="article">
     <meta property="og:title" content="<%- page.title ? page.title + ' — ' : '' %>Vue.js">

themes/vue/layout/partials/language_dropdown.ejs

@@ -8,5 +8,6 @@
     <li><a href="https://br.vuejs.org/<%- page.path %>" class="nav-link" target="_blank" rel="noopener">Português</a></li>
     <li><a href="https://fr.vuejs.org/<%- page.path %>" class="nav-link" target="_blank" rel="noopener">Français</a></li>
     <li><a href="https://vi.vuejs.org/<%- page.path %>" class="nav-link" target="_blank" rel="noopener">Tiếng Việt</a></li>
+    <li><a href="https://es.vuejs.org/<%- page.path %>" class="nav-link" target="_blank" rel="noopener">Español</a></li>
   </ul>
 </li>