[Bug] docs: typo in docs/cn/controller/design.md

[yao-wenbin]

Before Creating the Bug Report

• I found a bug, not just asking a question, which should be created in GitHub Discussions.

• I have searched the GitHub Issues and GitHub Discussions of this repository and believe that this is not a duplicate.

• I have confirmed that this bug belongs to the current repository, not other repositories of RocketMQ.

Runtime platform environment

MacOS 13.1 (22C65)

RocketMQ version

branch: develop

JDK Version

No response

Describe the Bug

I found a typo in docs/cn/controller/design.md

Steps to Reproduce

see in https://github.com/apache/rocketmq/blob/develop/docs/cn/controller/design.md line 128.

What Did You Expect to See?

fix the typo.

What Did You See Instead?

fix the typo just alright.

Additional Context

No response

[yao-wenbin]

#6942