add explain on some usage.

README.md

@@ -42,6 +42,16 @@ C:\msys64\uninstall.exe pr --confirm-command
 
 Java 环境是通过 [sdkman](https://sdkman.io/) 安装的，这有助于提供一个独立于 Windows 主机的环境。这样就可以支持便携式安装。Java 和 sbt 全部由 sdkman 管理，位于独立的目录 `/sdkman` 下。另一方面，jar 缓存文件安装在 `/cache`，这样我们就可以离线使用安装程序。所需的环境变量均已配置完成。
 
+### IDE（VSCode、IDEA等）集成
+
+在未启动目标IDE的情况下，打开MSYS2自带的MINGW64控制台，在命令行中输入目标IDE的启动执行文件路径，即可启动目标IDE并使用该环境。
+
+### 离线使用方法
+
+本安装包仅包含编译、测试SpinalHDL工程所需的文件，不包含各种IDE及其插件所需文件。
+由于不同人使用的开发环境、IDE版本各不相同，建议在在线机上安装该包，并启动编译、测试你的工程后，将安装目录复制到离线机使用。
+> 若需使用镜像下载可参考 [Coursier官方文档](https://get-coursier.io/blog/#mirrors) 。
+
 ### 如果想使用旧版本的 SpinalHDL 怎么办？
 
 创建issue，或者克隆此仓库然后自己修改。

README_en.md

@@ -49,6 +49,16 @@ It contains the [base](https://packages.msys2.org/package/base) package with oth
 
 The java environment is install through [sdkman](https://sdkman.io/) which helps to provide a standalone environment seperate from host Windows. So that portable using is possible. Java and sbt are all managed by sdkman in it's own directory `/sdkman`. On other way, jar cache file is installed in `/cache` so that we can use the installer offline.
 
+### IDE (VSCode, IDEA, etc.) Integration
+
+Without starting the target IDE, open the MSYS2 built-in MINGW64 console and enter the path of the target IDE's startup executable file in the command line to start the target IDE which use this environment.
+
+### Offline Usage Method
+
+This installation package only includes the files required for compiling and testing the SpinalHDL project, and does not include the files needed for various IDEs and their plugins.
+Since different people use different development environments and IDE versions, it is recommended to install this package on an online machine, and after starting the compilation and testing of your project, copy the installation directory to the offline machine.
+> For using mirror downloads, you can refer to the [Coursier official documentation](https://get-coursier.io/blog/#mirrors).
+
 ### What if I want to use an old version SpinalHDL?
 
 create issue, or clone this repos and modify yourself.