Added real world example for Chain

iluwatar · iluwatar · commit 1c2105dd6efb · 2015-05-14T23:30:05.000+03:00
diff --git a/README.md b/README.md
@@ -287,6 +287,7 @@ A programming idiom is a means of expressing a recurring construct in one or mor
 
 **Real world examples:**
 * [java.util.logging.Logger#log()](http://docs.oracle.com/javase/8/docs/api/java/util/logging/Logger.html#log%28java.util.logging.Level,%20java.lang.String%29)
+* [Apache Commons Chain](https://commons.apache.org/proper/commons-chain/index.html)
 
 ## <a name="command">Command</a> [&#8593;](#list-of-design-patterns)
 **Intent:** Encapsulate a request as an object, thereby letting you parameterize clients with different requests, queue or log requests, and support undoable operations.
