MDL-38509 Document the plugin deployment lockers in config-dist.php

config-dist.php

@@ -438,6 +438,16 @@ $CFG->admin = 'admin';
 //
 //      $CFG->disableupdatenotifications = true;
 //
+// Use the following flag to completely disable the Automatic updates deployment
+// feature and hide it from the server administration UI.
+//
+//      $CFG->disableupdateautodeploy = true;
+//
+// Use the following flag to completely disable the On-click add-on installation
+// feature and hide it from the server administration UI.
+//
+//      $CFG->disableonclickaddoninstall = true;
+//
 // As of version 2.4 Moodle serves icons as SVG images if the users browser appears
 // to support SVG.
 // For those wanting to control the serving of SVG images the following setting can