Clarify that the file attribute can refer to a directory as well.

PR: 31113


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@276836 13f79535-47bb-0310-9956-ffa450edef68

docs/manual/CoreTasks/dirname.html

@@ -14,10 +14,10 @@ Task to determine the directory path of a specified file.
 </p>
 <p> 
 When this task executes, it will set the specified property to the
-value of the specified file up to, but not including, the last path
-element. If the specified file is a path that ends in a filename,
-the filename will be dropped. If the specified file is just a filename,
-the directory will be the current directory.
+value of the specified file (or directory) up to, but not including,
+the last path element. If the specified file is a path that ends in a
+filename, the filename will be dropped. If the specified file is just
+a filename, the directory will be the current directory.
 </p>
 <h3>Parameters</h3>
 <table border="1" cellpadding="2" cellspacing="0">