Fix: Add missing sentencepiece installation in example code

README.md

@@ -171,6 +171,7 @@ Use the code below to get started with the model.
 <summary> Click to expand </summary>
 
 ```python
+!{sys.executable} -m pip install sentencepiece
 from transformers import T5Tokenizer, T5Model
 
 tokenizer = T5Tokenizer.from_pretrained("t5-large")