Fix Spanish link in language banner

Author: qwertygc

overrides/main.html

@@ -7,7 +7,7 @@
       <span>Other languages:</span>
       <a href="/doc/fr/{{ page.meta.path}}">Français</a> ⋅ 
       <a href="/doc/en/{{ page.meta.path}}">English</a> ⋅ 
-      <a href="/doc/en/{{ page.meta.path}}">Español</a>
+      <a href="/doc/es/{{ page.meta.path}}">Español</a>
     </div>
   </div>
    {% endif %}