Move static routes into a blueprint

and update templates

Routes:
* /help
* /rules
* /xmlns/nyaa
* /about (commented out)

nyaa/templates/view.html

@@ -191,7 +191,7 @@
 			<div class="modal-body">
 				<div class="alert alert-warning" role="alert">
 					Before submitting a report, please check that the torrent
-					actually breaks <a href="{{ url_for('site_rules') }}">the
+					actually breaks <a href="{{ url_for('site.rules') }}">the
 					rules</a>. Useless reports like "download is slow" or
 					"thanks" can get you banned from the site.
 				</div>