New Chat UI and Demo Mode

[zetavg]

On the dev branch, there's a new Chat UI and a new Demo Mode config as a simple and easy way to demonstrate new models.

However, the new version does not have the fine-tuning feature yet and is not backward compatible as it uses a new way to define how models are loaded, and also a new format of prompt templates (from LangChain).

LLM.Tuner.Chat.UI.in.Demo.Mode.mp4

For details, check the twlm-demo branch and the config_demo.yaml file and data_demo folder on that branch. It can be deployed to Lambda Demos or Hugging Face spaces.

The sample prompts are from the article Vicuna: An Open-Source Chatbot Impressing GPT-4 with 90%* ChatGPT Quality
.