Update package_installation.md

Author: maninhill

docs/installation/package_installation.md

@@ -1,3 +1,6 @@
+!!! Warning "**<font color="red">1Panel V2 离线版已正式发布！</font>** "    
+    - 1Panel V2 离线版已正式发布，[**点击查看详情**](https://1panel.cn/docs/v2/installation/package_installation/)。
+
 ## 1 环境要求
 
 !!! note ""