Add trailing newline to generated docs.

lib/main/build-site.js

@@ -63,7 +63,8 @@ function build(type) {
     // Wrap in raw tags to avoid Liquid template tag processing.
     '{% raw %}',
     _.trim($.html()),
-    '{% endraw %}'
+    '{% endraw %}',
+    ''
   ].join('\n');
 
   fs.writeFile(path.join(docPath, version + '.html'), html, util.pitch);