Extra clarification about where rpm task runs and what it does.

Submitted By: "Steve Loughran" <steve_l@iseran.com>


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@269070 13f79535-47bb-0310-9956-ffa450edef68

docs/manual/OptionalTasks/rpm.html

@@ -9,7 +9,8 @@
 <h2><a name="rpm">Rpm</a></h2>
 <h3>Description</h3>
 <p>
-  A basic task for invoking the rpm executable.
+  A basic task for invoking the rpm executable to build a linux installation
+  file. The task currently only works on Linux.
 </p>
 
 <h3>Parameters</h3>