Docs: Correct the documentation for the publishing function.

Patch by David Maus

doc/ChangeLog

@@ -1,3 +1,8 @@
+2010-03-01  Carsten Dominik  <carsten.dominik@gmail.com>
+
+	* org.texi (Publishing action): Correct the documentation for the
+	publishing function.
+
 2010-02-26  Carsten Dominik  <carsten.dominik@gmail.com>
 
 	* org.texi (The date/time prompt): Document that we accept dates

doc/org.texi

@@ -10156,10 +10156,11 @@ list of functions, which will all be called in turn.
 @tab Non-nil means, publish htmlized source.
 @end multitable
 
-The function must accept two arguments: a property list containing at least a
-@code{:publishing-directory} property, and the name of the file to be
-published.  It should take the specified file, make the necessary
-transformation (if any) and place the result into the destination folder.
+The function must accept three arguments: a property list containing at least
+a @code{:publishing-directory} property, the name of the file to be
+published, and the path to the publishing directory of the output file.  It
+should take the specified file, make the necessary transformation (if any)
+and place the result into the destination folder.
 
 @node Publishing options, Publishing links, Publishing action, Configuration
 @subsection Options for the HTML/La@TeX{} exporters