Add missing import and add information on which pip packages are needed

README.md

@@ -30,7 +30,11 @@ Extensive evaluations show the superiority of the proposed SpeechT5 framework on
 Use the code below to convert text into a mono 16 kHz speech waveform.
 
 ```python
+# Following pip packages need to be installed:
+# !pip install git+https://github.com/huggingface/transformers sentencepiece datasets
+
 from transformers import SpeechT5Processor, SpeechT5ForTextToSpeech, SpeechT5HifiGan
+from datasets import load_dataset
 import torch
 import soundfile as sf