Add `chat_template` to `tokenizer_config.json`

Adds an Alpaca style `chat_template` so that this checkpoint can be used conversationally.

tokenizer_config.json

@@ -7,6 +7,7 @@
     "rstrip": false,
     "single_word": false
   },
+  "chat_template": "{% for message in messages %}{% if message['role'] == 'system' %}{% endif %}{% if message['role'] == 'user' %}{{ '### Instruction:\n' }}{% endif %}{% if message['role'] == 'assistant' %}{{ '### Response:\n' }}{% endif %}{{ message['content'].strip() }}{% if not loop.last %}{{ '\n\n' }}{% endif %}{% if message['role'] == 'user' and loop.last %}{{ '### Response:\n' }}{% endif %}{% endfor %}",
   "clean_up_tokenization_spaces": false,
   "eos_token": {
     "__type": "AddedToken",