Update README.md

README.md

@@ -45,6 +45,7 @@ validation with English data can be easier if you don't speak all languages in y
 ### How to use the model
 #### Simple zero-shot classification pipeline
 ```python
+#!pip install transformers[sentencepiece]
 from transformers import pipeline
 text = "Angela Merkel is a politician in Germany and leader of the CDU"
 hypothesis_template = "This example is about {}"