Add env guidance for PowerShell

Author: webprofusion-chrisc

docs/getting-started/windows.md

@@ -90,19 +90,25 @@ npx mycoder "Your prompt here"
 ### Setting up API keys
 
 1. **Temporary Environment Variables**:
+
+   From the command prompt (CMD):
    ```
    set ANTHROPIC_API_KEY=your-api-key
    ```
-
-2. **Persistent Environment Variables**:
+   In a PowerShell session:
+   ```
+   $env:ANTHROPIC_API_KEY="your-api-key"
+   ```
+   
+3. **Persistent Environment Variables**:
    - Right-click on "This PC" or "My Computer"
    - Select "Properties"
    - Click "Advanced system settings"
    - Click "Environment Variables"
    - Under "User variables", click "New"
    - Add your API key (e.g., ANTHROPIC_API_KEY as variable name)
 
-3. **Using .env File**:
+4. **Using .env File**:
    - Create a file named `.env` in your project directory
    - Add your API key: `ANTHROPIC_API_KEY=your-api-key`
 
@@ -122,4 +128,4 @@ MyCoder can use a browser for research. On Windows:
 - **Node Version**: Ensure you're using Node.js 20+
 - **Path Issues**: Make sure npm global bin directory is in your PATH
 
-If you encounter any other issues, please check our [Discord community](https://discord.gg/5K6TYrHGHt) for help.
+If you encounter any other issues, please check our [Discord community](https://discord.gg/5K6TYrHGHt) for help.