add example explanation

app.py

@@ -74,6 +74,9 @@ if __name__ == "__main__":
             [`compute_transition_scores`](https://huggingface.co/docs/transformers/main/en/main_classes/text_generation#transformers.GenerationMixin.compute_transition_scores),
             which was added in `transformers` v4.26.0.
 
+            ⚠️ For instance, with the pre-populated input and its color coded output, you can see that
+            `google/flan-t5-base` struggles with arithmetics.
+
             🤗 Feel free to clone this demo and modify it to your needs 🤗
             """
         )