Mention Virtual MQ support in the changelog (#374)

Author: pg-yang

CHANGES.md

@@ -5,7 +5,7 @@ Release Notes.
 8.13.0
 ------------------
 
-**This release begins to adopt SkyWalking 9.3.0+ [Virtual Cache Analysis](https://skywalking.apache.org/docs/main/next/en/setup/service-agent/virtual-cache/).**
+**This release begins to adopt SkyWalking 9.3.0+ [Virtual Cache Analysis](https://skywalking.apache.org/docs/main/next/en/setup/service-agent/virtual-cache/),[Virtual MQ Analysis](https://skywalking.apache.org/docs/main/next/en/setup/service-agent/virtual-mq/)**
 
 * Support set-type in the agent or plugin configurations
 * Optimize ConfigInitializer to output warning messages when the config value is truncated.

docs/en/setup/service-agent/java-agent/Java-Plugin-Development-Guide.md

@@ -223,11 +223,9 @@ SkyWalking analysis MQ performance related metrics through the following tags.
 
 ```java
     public static final StringTag MQ_QUEUE = new StringTag(7, "mq.queue");
-    public static final StringTag MQ_BROKER = new StringTag(8, "mq.broker");
     public static final StringTag MQ_TOPIC = new StringTag(9, "mq.topic");
     public static final StringTag TRANSMISSION_LATENCY = new StringTag(15, "transmission.latency", false);
 ```
-* `mq.brokers` indicates MQ address ,SkyWalking organize the value as service . Both of consumer , producer must record the tag , and ensure the value is consistent .
 * `mq.queue`   indicates MQ queue name 
 * `mq.topic`   indicates MQ topic name , It's optional as some MQ don't hava concept of `topic`
 * `transmission.latency` The transmission latency from consumer to producer. Usually you needn't to record this tag manually, instead to call  `contextCarrier.extensionInjector().injectSendingTimestamp();` to record tag `sendingTimestamp` on producer side , and SkyWalking would record this tag on consumer side if `sw8-x` context carrier(from producer side) contains `sendingTimestamp`