Update author tag and events doc

Author: AlamuriLokesh

spring-kafka-docs/src/main/antora/modules/ROOT/pages/kafka/events.adoc

@@ -102,6 +102,7 @@ In addition, the `ConsumerStoppedEvent` has the following additional property:
 
 * `reason`:
 ** `NORMAL` - the consumer stopped normally (container was stopped).
+** `ABNORMAL` - the consumer stopped abnormally (container was stopped abnormally).
 ** `ERROR` - a `java.lang.Error` was thrown.
 ** `FENCED` - the transactional producer was fenced and the `stopContainerWhenFenced` container property is `true`.
 ** `AUTH` - an `AuthenticationException` or `AuthorizationException` was thrown and the `authExceptionRetryInterval` is not configured.

spring-kafka/src/main/java/org/springframework/kafka/event/ConsumerStoppedEvent.java

@@ -24,6 +24,7 @@
  * to restart a container that was stopped because a transactional producer was fenced.
  *
  * @author Gary Russell
+ * @author Lokesh Alamuri
  * @since 2.2
  *
  */
@@ -45,6 +46,8 @@ public enum Reason {
 
 		/**
 		 * The consumer was stopped because the container was stopped abnormally.
+		 * @since 4.0
+		 *
 		 */
 		ABNORMAL,