adds optgroup on local switcher

app/views/shared/_locale_switcher.html.erb

@@ -5,12 +5,14 @@
         <%= t("layouts.header.locale") %>
       </label>
       <select class="js-location-changer locale-switcher inline-block" name="locale-switcher" id="locale-switcher">
-        <% I18n.available_locales.map do |loc| %>
-          <option <%= "selected" if loc == I18n.locale %>
-                  value="<%= current_path_with_query_params(locale: loc) %>">
-            <%= name_for_locale(loc) %>
-          </option>
-        <% end %>
+        <optgroup label="<%= t('layouts.header.available_locales') %>">
+          <% I18n.available_locales.map do |loc| %>
+            <option <%= "selected" if loc == I18n.locale %>
+                    value="<%= current_path_with_query_params(locale: loc) %>">
+              <%= name_for_locale(loc) %>
+            </option>
+          <% end %>
+        </optgroup>
       </select>
     </form>
   </div>

config/locales/en.yml

@@ -185,6 +185,7 @@ en:
       transparency_url: https://transparency.consul
     header:
       administration: Administration
+      available_locales: Available languages
       debates: Debates
       external_link_blog: Blog
       external_link_opendata: Open data

config/locales/es.yml

@@ -185,6 +185,7 @@ es:
       transparency_url: https://transparency.consul
     header:
       administration: Administrar
+      available_locales: Idiomas disponibles
       debates: Debates
       external_link_blog: Blog
       external_link_opendata: Datos abiertos