change folder structure

samples/helloworld/src/main/java/org/springframework/shell/samples/helloworld/HelloWorldPlugin.java

@@ -4,7 +4,9 @@ import org.springframework.context.annotation.ComponentScan;
 import org.springframework.context.annotation.Configuration;
 
 @Configuration
-@ComponentScan({"org.springframework.shell.commands", "org.springframework.shell.converters"})
+@ComponentScan({"org.springframework.shell.commands", 
+				"org.springframework.shell.converters",
+				"org.springframework.shell.samples.helloworld.commands"})
 public class HelloWorldPlugin {