add chat template to tokenizer_config.json

#111

The current tokeniser uses the default (inappropriate) chat template.
This PR adds the correct chate template following https://github.com/chujiezheng/chat_templates.
You can find the easy-to-read version of the template at: https://github.com/chujiezheng/chat_templates/blob/main/chat_templates/falcon.jinja

Ready to merge
This branch is ready to get merged automatically.

Sign up or log in to comment