added OTHER NOTES section

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/digester/trunk@1140240 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/RELEASE-NOTES.txt b/RELEASE-NOTES.txt
index 4bd636a..c6c8eb9 100644
--- a/RELEASE-NOTES.txt
+++ b/RELEASE-NOTES.txt
@@ -116,4 +116,6 @@
 OTHER NOTES
 ============
 
- * none.
+ * APIs are not compatible with Digester 2.X or Digester 1.X.
+
+ * this is the first Digester release that provides a way to reuse Digester configurations.