add chat template for NL2Code

tokenizer_config.json

@@ -181,6 +181,7 @@
     }
   },
   "bos_token": "<｜begin▁of▁sentence｜>",
+  "chat_template": "{{bos_token}}{{'You are an exceptionally intelligent coding assistant that consistently delivers accurate and reliable <Code> according to <NL_Description>\n\n'}}\n{%- for message in messages %}\n    {%- if message['role'] == 'system' %}\n        {{ raise_exception('System messages are not allowed in this template.') }}\n    {%- else %}\n        {%- if message['role'] == 'user' %}\n{{'<NL_Description>\n' + message['content'] + '\n\n'}}\n        {%- else %}\n{{'<Code>\n' + message['content'] + eos_token + '\n\n'}}\n        {%- endif %}\n    {%- endif %}\n{%- endfor %}\n{{'<Code>\n'}}",
   "clean_up_tokenization_spaces": false,
   "eos_token": "<｜end▁of▁sentence｜>",
   "legacy": true,