Fix broken template file

See
4e3455f

The markup of a topdoc comment is handed to the template in
component.markup as per the new spec introduced in the referenced
commit. The default template uses component.html and does not show any
markup.

Updating the template to use the new spec fixes the problem.

lib/template.jade

@@ -27,7 +27,7 @@ html
 			.component
 				h2=component.name
 				.details=component.details
-				pre.html=component.html
+				pre.html=component.markup
 				pre.css=component.css