fix: picture path

Author: icey-yu

docs/guides/gettingStarted/admin.mdx

@@ -60,15 +60,15 @@ import Image4 from './assets/admin.jpg';
 
 点击下图的import按钮，导入仪表盘 
 
-![PC Web Interface](https://docs.openim.io/zh-Hans/assets/images/dashboard-bab5c385a6dbac9f919f494a94e2a49a.png)
+![dashboard.png](./assets/dashboard.png)
 
 拷贝 https://github.com/openimsdk/open-im-server/tree/main/config/grafana-template/Demo.json 内容到下图区域，接着点击load按钮
 
-![PC Web Interface](https://docs.openim.io/zh-Hans/assets/images/dashboard2-249cfe565b44bbf0eb8924889d858248.png)
-
-选择你的 Data Source和job , 自定义指标信息，如下图 ![PC Web Interface](https://docs.openim.io/zh-Hans/assets/images/dashboard3-277e7f05ed345b5b6c869324aec5d34f.png)
+![dashboard2](./assets/dashboard2.png)
 
+选择你的 Data Source和job , 即可导入指标信息，如下图 
 
+![dashboard3](./assets/dashboard3.png)
 
 ## **自定义dashboard**