Add chat template

tokenizer_config.json

@@ -238,5 +238,6 @@
       "tokenization_olmo_fast.OLMoTokenizerFast",
       "tokenization_olmo_fast.OLMoTokenizerFast"
     ]
-  }
+  },
+  "chat_template": "{{ eos_token }}{% for message in messages %}\n{% if message['role'] == 'user' %}\n{{ '<|user|>\n' + message['content'] }}\n{% elif message['role'] == 'assistant' %}\n{{ '<|assistant|>\n'  + message['content'] + eos_token }}\n{% endif %}\n{% if loop.last and add_generation_prompt %}\n{{ '<|assistant|>' }}\n{% endif %}\n{% endfor %}"
 }