docs: add emqx version note (#15706)

docs/en/20-third-party/09-emq-broker.md

@@ -16,6 +16,7 @@ The following preparations are required for EMQX to add TDengine data sources co
 
 Depending on the current operating system, users can download the installation package from the [EMQX official website](https://www.emqx.io/downloads) and execute the installation. After installation, use `sudo emqx start` or `sudo systemctl start emqx` to start the EMQX service.
 
+Note: this chapter is based on EMQX v4.4.5. Other version of EMQX probably change its user interface, configuration methods or functions.
 
 ## Create Database and Table
 

docs/zh/20-third-party/09-emq-broker.md

@@ -17,6 +17,7 @@ MQTT 是流行的物联网数据传输协议，[EMQX](https://github.com/emqx/em
 
 用户可以根据当前的操作系统，到 EMQX 官网下载安装包，并执行安装。下载地址如下：<https://www.emqx.io/zh/downloads>。安装后使用 `sudo emqx start` 或 `sudo systemctl start emqx` 启动 EMQX 服务。
 
+注意：本文基于 EMQX v4.4.5 版本，其他版本由于相关配置界面、配置方法以及功能可能随着版本升级有所区别。
 
 ## 创建数据库和表