MAVEN-707. Add encoding documentation. Thanks to Piotr Maj.

git-svn-id: https://svn.apache.org/repos/asf/maven/maven-1/plugins/trunk@113877 13f79535-47bb-0310-9956-ffa450edef68

javadoc/xdocs/properties.xml

@@ -210,6 +210,17 @@ tag2.scope=all
             </source>
           </td>
         </tr>
+        <tr>
+          <td>maven.javadoc.additionalparam</td>
+          <td>Yes</td>
+          <td>
+            Specifies additional parameters added to the javadoc command line.
+            <p>Example (sets generated Javadocs encoding to utf-8):</p>
+            <source>
+maven.javadoc.additionalparam=-charset utf-8
+            </source>
+          </td>
+        </tr>
       </table>
     </section>
   </body>