add an alternative prompt template

README.md

@@ -57,3 +57,13 @@ It is supported by:
 {prompt}<|im_end|>
 <|im_start|>assistant
 ```
+
+Also working with Basic Mistral format:
+
+```plaintext
+<|system|>
+</s>
+<|user|>
+{prompt}</s>
+<|assistant|>
+```