docs: update readme main (#21401)

* docs: update readme with libgflags

* docs: update README-CN.md

README-CN.md

@@ -15,7 +15,7 @@
 [![Coverage Status](https://coveralls.io/repos/github/taosdata/TDengine/badge.svg?branch=develop)](https://coveralls.io/github/taosdata/TDengine?branch=develop)
 [![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/4201/badge)](https://bestpractices.coreinfrastructure.org/projects/4201)
 
-简体中文 | [English](README.md) | 很多职位正在热招中，请看[这里](https://www.taosdata.com/cn/careers/)
+简体中文 | [English](README.md) | [TDengine 云服务](https://cloud.taosdata.com/?utm_medium=cn&utm_source=github) | 很多职位正在热招中，请看[这里](https://www.taosdata.com/cn/careers/)
 
 # TDengine 简介