Add default chat template to tokenizer_config.json

tokenizer_config.json

@@ -3,5 +3,6 @@
   "clean_up_tokenization_spaces": true,
   "eos_token": "<|endoftext|>",
   "model_max_length": 2048,
-  "tokenizer_class": "PreTrainedTokenizerFast"
-}
+  "tokenizer_class": "PreTrainedTokenizerFast",
+  "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 %}"
+}