DOCS-647 security blurb

Author: Sam Kleinman

source/security.txt

@@ -2,11 +2,26 @@
 Security
 ========
 
+The documents outline basic security practices and risk management
+strategies. Additionally, this section includes :ref:`tutorials` that
+outline basic network filter and firewall rules to configure trusted
+environments for MongoDB.
+
+Strategies and Practices
+------------------------
+
+.. toctree::
+   :maxdepth: 2
+
+   /administration/security
+   /administration/vulnerability-notification
+
+Tutorials
+---------
+
 .. toctree::
-   :maxdepth: 3
+   :maxdepth: 2
 
-   administration/security.txt
-   administration/vulnerability-notification.txt
-   tutorial/configure-linux-iptables-firewall.txt
-   tutorial/configure-windows-netsh-firewall.txt
-   tutorial/control-access-to-mongodb-with-authentication.txt
+   /tutorial/configure-linux-iptables-firewall
+   /tutorial/configure-windows-netsh-firewall
+   /tutorial/control-access-to-mongodb-with-authentication