docs ： rocketmq quickstart sync to 2.1/2.2 (#909)

i18n/en/docusaurus-plugin-content-docs/version-v2.1/user/quickstart.md

@@ -218,3 +218,26 @@ sh seata-server.sh -p 8091 -h 127.0.0.1 -m file
 ### Step 5: Run example
 
 Go to samples repo: [seata-samples/at-samples](https://github.com/apache/incubator-seata-samples/tree/master/at-sample), and find a suitable dependency setup. Start `Account`, `Storage`, `Order`, `Business` services accordingly.
+
+## RocketMQ Integration to Seata
+
+Using RocketMQ as a participant in seata global transaction is simple,
+First, make sure you have introduced seata-all or springboot-starter of seata dependency.
+
+Create the producer by `SeataMQProducerFactory`, then send messages by  `SeataMQProducer`. Here is an example:
+```java
+public class BusinessServiceImpl implements BusinessService {
+    private static final String NAME_SERVER = "127.0.0.1:9876";
+    private static final String PRODUCER_GROUP = "test-group";
+    private static final String TOPIC = "test-topic";
+    private static SeataMQProducer producer= SeataMQProducerFactory.createSingle(NAME_SERVER, PRODUCER_GROUP);
+
+    public void purchase(String userId, String commodityCode, int orderCount) {
+      producer.send(new Message(TOPIC, "testMessage".getBytes(StandardCharsets.UTF_8)));
+      //do something
+    }
+}
+```
+The effect of this approach is that the production message acts as a participant RM in the seata global transaction. When the 1st phase of the global transaction is completed, the MQ message will be committed or rollback based on the transaction 2nd phase’s request,
+the message will not be consumed until then.
+Note: If there is no xid in the current thread, the producer will degrade to a normal send instead of sending a half-message.

i18n/en/docusaurus-plugin-content-docs/version-v2.2/user/quickstart.md

@@ -218,3 +218,26 @@ sh seata-server.sh -p 8091 -h 127.0.0.1 -m file
 ### Step 5: Run example
 
 Go to samples repo: [seata-samples/at-samples](https://github.com/apache/incubator-seata-samples/tree/master/at-sample), and find a suitable dependency setup. Start `Account`, `Storage`, `Order`, `Business` services accordingly.
+
+## RocketMQ Integration to Seata
+
+Using RocketMQ as a participant in seata global transaction is simple,
+First, make sure you have introduced seata-all or springboot-starter of seata dependency.
+
+Create the producer by `SeataMQProducerFactory`, then send messages by  `SeataMQProducer`. Here is an example:
+```java
+public class BusinessServiceImpl implements BusinessService {
+    private static final String NAME_SERVER = "127.0.0.1:9876";
+    private static final String PRODUCER_GROUP = "test-group";
+    private static final String TOPIC = "test-topic";
+    private static SeataMQProducer producer= SeataMQProducerFactory.createSingle(NAME_SERVER, PRODUCER_GROUP);
+
+    public void purchase(String userId, String commodityCode, int orderCount) {
+      producer.send(new Message(TOPIC, "testMessage".getBytes(StandardCharsets.UTF_8)));
+      //do something
+    }
+}
+```
+The effect of this approach is that the production message acts as a participant RM in the seata global transaction. When the 1st phase of the global transaction is completed, the MQ message will be committed or rollback based on the transaction 2nd phase’s request,
+the message will not be consumed until then.
+Note: If there is no xid in the current thread, the producer will degrade to a normal send instead of sending a half-message.

i18n/zh-cn/docusaurus-plugin-content-docs/version-v2.1/user/quickstart.md

@@ -216,3 +216,26 @@ sh seata-server.sh -p 8091 -h 127.0.0.1 -m file
 ### 步骤 5: 运行示例
 
 示例仓库: [seata-samples/at-samples](https://github.com/apache/incubator-seata-samples/tree/master/at-sample)。找到合适的依赖项设置，按顺序启动 `Account`, `Storage`, `Order`, `Business` 服务。
+
+## RocketMQ 接入 Seata
+
+使用RocketMQ作为Seata分布式事务的参与者很简单，先确保已经引入了seata-all或者seata的springboot-starter依赖。
+
+然后通过`SeataMQProducerFactory`创建生产者，然后通过 `SeataMQProducer` 可以直接使用 RocketMQ 发送消息。以下是一个例子：
+
+
+```java
+public class BusinessServiceImpl implements BusinessService {
+    private static final String NAME_SERVER = "127.0.0.1:9876";
+    private static final String PRODUCER_GROUP = "test-group";
+    private static final String TOPIC = "test-topic";
+    private static SeataMQProducer producer= SeataMQProducerFactory.createSingle(NAME_SERVER, PRODUCER_GROUP);
+
+    public void purchase(String userId, String commodityCode, int orderCount) {
+      producer.send(new Message(TOPIC, "testMessage".getBytes(StandardCharsets.UTF_8)));
+      //do something
+    }
+}
+```
+这样达到的效果是：生产消息作为Seata分布式事务的参与者RM，当全局事务的一阶段完成，这个MQ消息会根据二阶段要求commit/rollback进行消息的提交或撤回，在此之前消息不会被消费。
+注: 当前线程中如果没有xid，该producer会退化为普通的send，而不是发送半消息

i18n/zh-cn/docusaurus-plugin-content-docs/version-v2.2/user/quickstart.md

@@ -216,3 +216,27 @@ sh seata-server.sh -p 8091 -h 127.0.0.1 -m file
 ### 步骤 5: 运行示例
 
 示例仓库: [seata-samples/at-samples](https://github.com/apache/incubator-seata-samples/tree/master/at-sample)。找到合适的依赖项设置，按顺序启动 `Account`, `Storage`, `Order`, `Business` 服务。
+
+
+## RocketMQ 接入 Seata
+
+使用RocketMQ作为Seata分布式事务的参与者很简单，先确保已经引入了seata-all或者seata的springboot-starter依赖。
+
+然后通过`SeataMQProducerFactory`创建生产者，然后通过 `SeataMQProducer` 可以直接使用 RocketMQ 发送消息。以下是一个例子：
+
+
+```java
+public class BusinessServiceImpl implements BusinessService {
+    private static final String NAME_SERVER = "127.0.0.1:9876";
+    private static final String PRODUCER_GROUP = "test-group";
+    private static final String TOPIC = "test-topic";
+    private static SeataMQProducer producer= SeataMQProducerFactory.createSingle(NAME_SERVER, PRODUCER_GROUP);
+
+    public void purchase(String userId, String commodityCode, int orderCount) {
+      producer.send(new Message(TOPIC, "testMessage".getBytes(StandardCharsets.UTF_8)));
+      //do something
+    }
+}
+```
+这样达到的效果是：生产消息作为Seata分布式事务的参与者RM，当全局事务的一阶段完成，这个MQ消息会根据二阶段要求commit/rollback进行消息的提交或撤回，在此之前消息不会被消费。
+注: 当前线程中如果没有xid，该producer会退化为普通的send，而不是发送半消息