add link to notebook for fine-tuning example (#9)

- add link to notebook for fine-tuning example (db90148827abba6b0194bc5afb6763a59ce03560)


Co-authored-by: Mathijs Hollemans <Matthijs@users.noreply.huggingface.co>

README.md

@@ -107,6 +107,10 @@ speech = model.generate_speech(inputs["input_ids"], speaker_embeddings, vocoder=
 sf.write("speech.wav", speech.numpy(), samplerate=16000)
 ```
 
+### Fine-tuning the Model
+
+Refer to [this Colab notebook](https://colab.research.google.com/drive/1i7I5pzBcU3WDFarDnzweIj4-sVVoIUFJ) for an example of how to fine-tune SpeechT5 for TTS on a different dataset or a new language.
+
 # Training Details
 
 ## Training Data