Update AGENTS setup guide to English

AGENTS.md

@@ -0,0 +1,38 @@
+# AGENTS Setup Guide
+
+This repository requires environment configuration to build and run the .NET 9.0 projects. Run the installation script below with **sudo** or **root** privileges.
+
+## Steps in `setup.sh`
+
+1. Update and upgrade the system:
+   ```bash
+   apt-get update && apt-get upgrade -y
+   ```
+2. Install basic dependencies (`wget`, `apt-transport-https`, `ca-certificates`):
+   ```bash
+   apt-get install -y wget apt-transport-https ca-certificates
+   ```
+3. Add the Microsoft package key and update package lists:
+   ```bash
+   wget https://packages.microsoft.com/config/ubuntu/$(lsb_release -rs)/packages-microsoft-prod.deb
+   dpkg -i packages-microsoft-prod.deb
+   apt-get update
+   ```
+4. Install **.NET SDK 9.0**:
+   ```bash
+   apt-get install -y dotnet-sdk-9.0
+   ```
+   Verify the installation:
+   ```bash
+   dotnet --version
+   ```
+5. (Optional) Remove old packages:
+   ```bash
+   apt-get autoremove -y
+   ```
+
+## Notes from the README
+
+- Use the latest version of **Visual Studio** or **Visual Studio Code**.
+- Ensure the matching runtime version of the SDK is installed as indicated by the project.
+- You can also run the Equinox Project in Visual Studio Code on Windows, Linux or macOS.