Add favicon link

views/layout.jade

@@ -3,6 +3,7 @@ html
   head
     title= title
     link(rel='stylesheet', href='/stylesheets/style.css')
+    link(rel="icon", type="image/x-icon", href="/favicon.ico")
     link(href="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css", rel="stylesheet")
     script(src="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js")
   body