docs: update README

Author: ChenZiHong-Gavin

README.md

@@ -46,6 +46,22 @@ Experience it on the [OpenXLab Application Center](https://openxlab.org.cn/apps/
 
 ### Run from PyPI
 
+1. Install GraphGen
+   ```bash
+   pip install graphg
+   ```
+
+2. Run in CLI
+   ```bash
+   SYNTHESIZER_MODEL=your_synthesizer_model_name \
+   SYNTHESIZER_BASE_URL=your_base_url_for_synthesizer_model \
+   SYNTHESIZER_API_KEY=your_api_key_for_synthesizer_model \
+   TRAINEE_MODEL=your_trainee_model_name \
+   TRAINEE_BASE_URL=your_base_url_for_trainee_model \
+   TRAINEE_API_KEY=your_api_key_for_trainee_model \
+   graphg --output_dir cache
+   ```
+
 ### Run from Source
 
 1. Install dependencies