Improved Facade Javadoc

facade/src/main/java/com/iluwatar/facade/App.java

@@ -2,9 +2,15 @@ package com.iluwatar.facade;
 
 /**
  * 
- * Facade ({@link DwarvenGoldmineFacade}) provides simpler interface to subsystem.
+ * The Facade design pattern is often used when a system is very complex or difficult 
+ * to understand because the system has a large number of interdependent classes or 
+ * its source code is unavailable. This pattern hides the complexities of the larger 
+ * system and provides a simpler interface to the client. It typically involves a single 
+ * wrapper class which contains a set of members required by client. These members access 
+ * the system on behalf of the facade client and hide the implementation details.
  * <p>
- * http://en.wikipedia.org/wiki/Facade_pattern
+ * In this example the Facade is ({@link DwarvenGoldmineFacade}) and it provides a simpler 
+ * interface to the goldmine subsystem.
  * 
  */
 public class App {