zipgroupfileset is-a fileset. PR 47725

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@807533 13f79535-47bb-0310-9956-ffa450edef68

docs/manual/CoreTasks/zip.html

@@ -398,6 +398,9 @@ Collection</a>s are used to select groups of files to archive.</p>
 merged into the archive. Each file found in this fileset is added to the archive 
 the same way that <i>zipfileset src</i> files are added.</p>
 
+<p><code>&lt;zipgroupfileset&gt;</code> is
+  a <a href="../CoreTypes/fileset.html">fileset</a> and supports all
+  of its attributes and nested elements.</a>
 
 <h3>Examples</h3>
 <pre>  &lt;zip destfile=&quot;${dist}/manual.zip&quot;