Update README.md

Format must be user > assistant > user.
Using system > user method gives an error: "An error occurred during link analysis: Conversation roles must alternate user/assistant/user/assistant/..."

README.md

@@ -123,9 +123,11 @@ If you want to use Hugging Face `transformers` to generate text, you can do some
 from transformers import pipeline
 
 messages = [
-    {"role": "system", "content": "You are a pirate chatbot who always responds in pirate speak!"},
-    {"role": "user", "content": "Who are you?"},
+    {"role": "user", "content": "What is your favourite condiment?"},
+    {"role": "assistant", "content": "Well, I'm quite partial to a good squeeze of fresh lemon juice. It adds just the right amount of zesty flavour to whatever I'm cooking up in the kitchen!"},
+    {"role": "user", "content": "Do you have mayonnaise recipes?"}
 ]
+
 chatbot = pipeline("text-generation", model="mistralai/Mistral-7B-Instruct-v0.3")
 chatbot(messages)
 ```