added link to /cookbook/security/force_https.

Author: aitboudad

cookbook/routing/scheme.rst

@@ -69,4 +69,5 @@ to always use ``http``.
     The Security component provides another way to enforce HTTP or HTTPS via
     the ``requires_channel`` setting. This alternative method is better suited
     to secure an "area" of your website (all URLs under ``/admin``) or when
-    you want to secure URLs defined in a third party bundle.
+    you want to secure URLs defined in a third party bundle (see
+    :doc:`/cookbook/security/force_https` for more details).