添加部分注释，修复一些功能

templates/partials/footer.html

@@ -52,7 +52,7 @@
           <li class="footer__extra-link-item" data-dropdown-target="#menu-footer-lang">
             <span><span class="icon icon-global"></span> Language <span class="icon icon-expand_less"></span></span>
             <ol class="dropdown-target menu" id="menu-footer-lang">
-            {% for item in builtin.VIEW_LANGS %}
+            {% for item in model.builtin.VIEW_LANGS %}
               <li class="menu__item"><a class="menu__link" href="/lang/{{ item.code }}">{{ item.name }}</a></li>
             {% endfor %}
             </ol>
@@ -61,7 +61,7 @@
       </div>
       <div class="footer__extra-right">
         <ol class="clearfix">
-        {% for html in builtin.FOOTER_EXTRA_HTMLS %}
+        {% for html in model.builtin.FOOTER_EXTRA_HTMLS %}
           <li class="footer__extra-link-item">{{ html|safe }}</li>
         {% endfor %}
         </ol>