[RIP-9] Add the introduction of the batch message samples in RocketMQ (#792)
[RIP-9] Add the introduction of the batch message samples in RocketMQ (#792)

[RIP-9] Add the introduction of the batch message samples in RocketMQ

DR-YangLong/RocketMQ,Vansee/RocketMQ,DR-YangLong/RocketMQ