Updated greeting message in controller

Signed-off-by: Izisisaac <goisaac05@1utar.my>

Author: goisaac05-a11y

complete/src/main/java/com/example/restservice/GreetingController.java

@@ -9,7 +9,7 @@
 @RestController
 public class GreetingController {
 
-  private static final String template = "Hello, %s!";
+  private static final String template = "Hello, %s! Welcome to our REST API.";
   private final AtomicLong counter = new AtomicLong();
 
   @GetMapping("/greeting")