docs: #590 refactor and add explanation for business delegate (#1686)

Type: docs and refactoring

Co-authored-by: Subhrodip Mohanta <hello@subho.xyz>

business-delegate/src/main/java/com/iluwatar/business/delegate/App.java

@@ -33,9 +33,9 @@ package com.iluwatar.business.delegate;
  * retrieved through service lookups. The Business Delegate itself may contain business logic too
  * potentially tying together multiple service calls, exception handling, retrying etc.
  *
- * <p>In this example the client ({@link Client}) utilizes a business delegate (
- * {@link BusinessDelegate}) to execute a task. The Business Delegate then selects the appropriate
- * service and makes the service call.
+ * <p>In this example the client ({@link MobileClient}) utilizes a business delegate (
+ * {@link BusinessDelegate}) to search for movies in video streaming services. The Business Delegate
+ * then selects the appropriate service and makes the service call.
  */
 public class App {
 
@@ -46,18 +46,16 @@ public class App {
    */
   public static void main(String[] args) {
 
+    // prepare the objects
     var businessDelegate = new BusinessDelegate();
     var businessLookup = new BusinessLookup();
-    businessLookup.setEjbService(new EjbService());
-    businessLookup.setJmsService(new JmsService());
-
+    businessLookup.setNetflixService(new NetflixService());
+    businessLookup.setYouTubeService(new YouTubeService());
     businessDelegate.setLookupService(businessLookup);
-    businessDelegate.setServiceType(ServiceType.EJB);
 
-    var client = new Client(businessDelegate);
-    client.doTask();
-
-    businessDelegate.setServiceType(ServiceType.JMS);
-    client.doTask();
+    // create the client and use the business delegate
+    var client = new MobileClient(businessDelegate);
+    client.playbackMovie("Die Hard 2");
+    client.playbackMovie("Maradona: The Greatest Ever");
   }
 }