add canonical link to latest

Author: Peter Krautzberger

_themes/sphinx-bootstrap/layout.html

@@ -82,6 +82,15 @@
         <title>{{ title|striptags|e }}{{ titlesuffix }}</title>
     {%- endblock %}
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <link rel="canonical" href="http://docs.mathjax.org/en/latest
+{%- for word in pagename.split('/') -%}
+    {%- if word != 'index' -%}
+        {%- if word != '' -%}
+            /{{ word }}
+        {%- endif -%}
+    {%- endif -%}
+{%- endfor -%}
+.html">
     <link href='http://fonts.googleapis.com/css?family=Crete+Round' rel='stylesheet' type='text/css'>
     <link rel="stylesheet" href="{{ pathto('_static/' + style, 1) }}" type="text/css"/>
     <link rel="stylesheet" href="{{ pathto('_static/pygments.css', 1) }}" type="text/css"/>