Added real world example for Builder.

Author: iluwatar

README.md

@@ -76,6 +76,7 @@ Behavioral patterns are concerned with algorithms and the assignment of responsi
 
 **Real world examples:**
 * [java.lang.StringBuilder](http://docs.oracle.com/javase/8/docs/api/java/lang/StringBuilder.html)
+* [Apache Camel builders](https://github.com/apache/camel/tree/0e195428ee04531be27a0b659005e3aa8d159d23/camel-core/src/main/java/org/apache/camel/builder)
 
 ## <a name="factory-method">Factory Method</a> [&#8593;](#list-of-design-patterns)
 **Intent:** Define an interface for creating an object, but let subclasses decide which class to instantiate. Factory Method lets a class defer instantiation to subclasses.