Fill out sysadmin user-settings

system-admin-guide/C/user-settings.page

@@ -10,4 +10,19 @@
 
   <title>User Settings</title>
 
+<section id="defaults">
+  <title>Pre-seed user defaults</title>
+  <links style="2column" type="topic"/>
+</section>
+
+<section id="email">
+  <title>Set up email and calendar</title>
+  <links style="2column" type="topic"/>
+</section>
+
+<section id="lockdown">
+  <title>Lock down settings</title>
+  <links style="2column" type="topic"/>
+</section>
+
 </page>