Add site description

docs/readthedocs_theme/base.html

@@ -6,6 +6,7 @@
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   {% block htmltitle %}
   <title>{{ page_title }}</title>
+  {% if page_description %}<meta name="description" content="{{ page_description }}">{% endif %}
   {% endblock %}
 
   {# CSS #}
@@ -65,7 +66,7 @@
               {{ content }}
             </div>
           </div>
-	  {%- block footer %} 
+	  {%- block footer %}
           {% include "footer.html" %}
 	  {% endblock %}
         </div>

mkdocs.yml

 site_name: Sequelize | The Node.js ORM
+site_description: Sequelize is a promise-based ORM for Node.js and io.js. It supports the dialects PostgreSQL, MySQL, MariaDB, SQLite and MSSQL.
 theme: ""
 theme_dir: docs/readthedocs_theme
 repo_url: https://github.com/sequelize/sequelize