Descriptor of jacoco-maven-plugin should include "help" mojo (#559)

diff --git a/org.jacoco.doc/docroot/doc/changes.html b/org.jacoco.doc/docroot/doc/changes.html
index e5dc783..dcebea1 100644
--- a/org.jacoco.doc/docroot/doc/changes.html
+++ b/org.jacoco.doc/docroot/doc/changes.html
@@ -55,6 +55,8 @@
       (GitHub <a href="https://github.com/jacoco/jacoco/issues/541">#541</a>).</li>
   <li>Reduced chance of conflict with other agents
       (GitHub <a href="https://github.com/jacoco/jacoco/issues/555">#555</a>).</li>
+  <li>Restored Maven <code>help</code> goal that was missing in version 0.7.9
+      (GitHub <a href="https://github.com/jacoco/jacoco/issues/559">#559</a>).</li>
 </ul>
 
 <h3>Non-functional Changes</h3>