Merge pull request #3202 from sequelize/feature/canonical-tag

Add canonical tag to theme template

docs/readthedocs_theme/base.html

@@ -7,6 +7,7 @@
   {% block htmltitle %}
   <title>{{ page_title }}</title>
   {% if page_description %}<meta name="description" content="{{ page_description }}">{% endif %}
+  {% if canonical_url %}<link rel="canonical" href="{{ canonical_url }}">{% endif %}
   {% endblock %}
 
   {# CSS #}