Adding NOTICE file.
diff --git a/NOTICE b/NOTICE
new file mode 100644
index 0000000..396bb00
--- /dev/null
+++ b/NOTICE
@@ -0,0 +1,5 @@
+Apache Slingpackager
+Copyright 2020 The Apache Software Foundation
+
+This product includes software developed at
+The Apache Software Foundation (http://www.apache.org/).
\ No newline at end of file