add chatml template

tokenizer_config.json

@@ -85,5 +85,6 @@
       "single_word": false,
       "special": true
     }
-  }
+  },
+  "chat_template": "{% for message in messages %}{{'<|im_start|>' + message['role'] + '\n' + message['content'] + '<|im_end|>' + '\n'}}{% endfor %}{% if add_generation_prompt %}{{ '<|im_start|>assistant\n' }}{% endif %}"
 }