Merge pull request #6135 from taosdata/docs/Update-Latest-Feature

[TD-4202] <docs>: fix Grafana plugin installation directory.

documentation20/cn/09.connections/docs.md

@@ -16,7 +16,7 @@ TDengine的Grafana插件在安装包的/usr/local/taos/connector/grafanaplugin
 以CentOS 7.2操作系统为例，将grafanaplugin目录拷贝到/var/lib/grafana/plugins目录下，重新启动grafana即可。
 
 ```bash
-sudo cp -rf /usr/local/taos/connector/grafanaplugin /var/lib/grafana/tdengine
+sudo cp -rf /usr/local/taos/connector/grafanaplugin /var/lib/grafana/plugins/tdengine
 ```
 
 ### 使用 Grafana