Added missing copyright header

in.bytehue.messaging.mqtt5.api/src/main/java/in/bytehue/messaging/mqtt5/api/MqttCommandExtension.java

@@ -1,10 +1,25 @@
+/*******************************************************************************
+ * Copyright 2020-2023 Amit Kumar Mondal
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License.  You may obtain a copy
+ * of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ ******************************************************************************/
 package in.bytehue.messaging.mqtt5.api;
 
 import org.osgi.annotation.versioning.ConsumerType;
 
 /**
- * {@link MqttCommandExtension} is primarily used to provide more information
- * to be displayed in MQTT Gogo command.
+ * {@link MqttCommandExtension} is primarily used to provide more information to
+ * be displayed in MQTT Gogo command.
  *
  * @since 1.0
  */