Add missing pygments css link

Author: Blendify

sphinx_rtd_theme/layout.html

@@ -42,7 +42,9 @@
   {% if not READTHEDOCS %}
     <link rel="stylesheet" href="{{ pathto('_static/' + style, 1) }}" type="text/css" />
   {% endif %}
-
+  
+  <link rel="stylesheet" href="{{ pathto('_static/pygments.css', 1) }}" type="text/css" />
+  
   {% for cssfile in css_files %}
     <link rel="stylesheet" href="{{ pathto(cssfile, 1) }}" type="text/css" />
   {% endfor %}