Added new version to doap.rdf.
diff --git a/doap.rdf b/doap.rdf
index 4c6931b..6e1b36e 100644
--- a/doap.rdf
+++ b/doap.rdf
@@ -110,6 +110,13 @@
     <release>
         <Version>
             <name>Apache FreeMarker</name>
+            <created>2021-02-16</created>
+            <revision>2.3.31</revision>
+        </Version>
+    </release>
+    <release>
+        <Version>
+            <name>Apache FreeMarker</name>
             <created>2020-03-05</created>
             <revision>2.3.30</revision>
         </Version>