docs: add license information in readme

README.md

@@ -19,9 +19,13 @@ A experimental model train on dapu, hailu, raoping, sixian,zhaoan five dialect
 - Use speaker embedding encoder
 - Use language embedding
 
-### Model Sources
+## Model Sources
 
 <!-- Provide the basic links for the model. -->
 
 - **Repository:** [coqui-ai/TTS](https://github.com/coqui-ai/TTS)
-- **Demo:** [Hugging Face Space](https://huggingface.co/spaces/formospeech/taiwanese-hakka-tts)
+- **Demo:** [Hugging Face Space](https://huggingface.co/spaces/formospeech/taiwanese-hakka-tts)
+
+## License
+
+License to use this model is covered by the [CC-BY-4.0](https://creativecommons.org/licenses/by/4.0/). By downloading the public and release version of the model, you accept the terms and conditions of the [CC-BY-4.0](https://creativecommons.org/licenses/by/4.0/) license.