Added reference to the <tag> option in JavaDoc.

(Is this the correct position? Someone hit me with a cluestick if I should
have added it at the top of the section or in a different section.)


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@271602 13f79535-47bb-0310-9956-ffa450edef68

WHATSNEW

@@ -199,6 +199,10 @@ Other changes:
   addition to the files matched by your patterns.  There now is a new
   attribute to suppress this behavior.
 
+* <javadoc> now supports a <tag> nested element to provide the -tag option
+  to the standard Java 1.4 doclet. The element is ignored when not running
+  on Java 1.4.
+
 Changes from Ant 1.4 to Ant 1.4.1
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