feat: Add chat template

tokenizer_config.json

@@ -8,5 +8,6 @@
   "model_max_length": 2048,
   "name_or_path": "tiiuae/falcon_tokenizer",
   "special_tokens_map_file": null,
-  "tokenizer_class": "PreTrainedTokenizerFast"
+  "tokenizer_class": "PreTrainedTokenizerFast",
+  "chat_template": "{% if messages[0]['role'] == 'system' %}{% set system_message = messages[0]['content'] %}{% set messages = messages[1:] %}{% else %}{% set system_message = '' %}{% endif %}{{ system_message | trim }}{% for message in messages %}{% if (message['role'] == 'user') != (loop.index0 % 2 == 0) %}{{ raise_exception('Conversation roles must alternate user/assistant/user/assistant/...') }}{% endif %}{% set content = message['content'].replace('\r\n', '\n').replace('\n\n', '\n') %}{{ '\n\n' + message['role'] | capitalize + ': ' + content | trim }}{% endfor %}{% if add_generation_prompt %}{{ '\n\nAssistant:' }}{% endif %}"
 }