Add print css link

layouts/partials/head.html

@@ -15,7 +15,7 @@
   {{ end }}
 
   <!-- CSS -->
-  <link rel="stylesheet" href="{{ .Site.BaseURL }}css/print.css">
+  <link rel="stylesheet" href="{{ .Site.BaseURL }}css/print.css" media="print">
   <link rel="stylesheet" href="{{ .Site.BaseURL }}css/poole.css">
   <link rel="stylesheet" href="{{ .Site.BaseURL }}css/syntax.css">
   <link rel="stylesheet" href="{{ .Site.BaseURL }}css/hyde.css">