Fix missing CSS include that got lost in rebase of gh-153

Author: rgommers

Diff for: layouts/partials/css.html

@@ -24,5 +24,6 @@
 <!-- Custom CSS -->
 <link rel="stylesheet" type="text/css" href="{{ "css/styles.css" | relURL }}" />
 <link rel="stylesheet" type="text/css" href="{{ "css/shell.css" | relURL }}" />
+<link rel="stylesheet" type="text/css" href="{{ "css/section2.css" | relURL }}" />
 <link rel="stylesheet" type="text/css" href="{{ "css/tabs.css" | relURL }}" />
 <link rel="stylesheet" type="text/css" href="{{ "css/content.css" | relURL }}" />