docs: Add missing documents

Author: whatasame

src/main/java/org/springframework/data/redis/connection/RedisStreamCommands.java

@@ -922,11 +922,17 @@ public String getConsumerName() {
 			return consumerName;
 		}
 
+		/**
+		 * @return can be {@literal null}.
+		 */
 		@Nullable
 		public Duration getIdle() {
 			return idle;
 		}
 
+		/**
+		 * @return can be {@literal null}.
+		 */
 		@Nullable
 		public Long getIdleMillis() {
 			if (idle == null) {

src/main/java/org/springframework/data/redis/core/DefaultStreamOperations.java

@@ -57,6 +57,7 @@
  * @author Marcin Zielinski
  * @author John Blum
  * @author jinkshower
+ * @author Jeonggyu Choi
  * @since 2.2
  */
 class DefaultStreamOperations<K, HK, HV> extends AbstractOperations<K, Object> implements StreamOperations<K, HK, HV> {

src/main/java/org/springframework/data/redis/core/StreamOperations.java

@@ -55,6 +55,7 @@
  * @author Marcin Zielinski
  * @author John Blum
  * @author jinkshower
+ * @author Jeonggyu Choi
  * @since 2.2
  */
 public interface StreamOperations<K, HK, HV> extends HashMapperProvider<HK, HV> {