chat.petals integration with Hugging Face Spaces

Currently, you can use the model either directly, via [this notebook](https://colab.research.google.com/drive/1DqaqGkI6ab92WeXDGMStWt_l8BPHUaIj#scrollTo=OJ7AFOumIYlY), or through http://chat.petals.ml/ .

The latter is a self-hosted chat app that runs code similar to the colab notebook, but wraps it with a simple web server. The source code is available [here](https://github.com/borzunov/chat.petals.ml).

It would be great if anybody could fork the chat project and reuse it for their pet projects. Thing is, not everyone has a server to host that web server - and it is not always convenient to share jupyter notebooks for everything.

To make it easier to create similar apps, we can create an example with Spaces. [Hugging Face Spaces](https://huggingface.co/spaces/launch) allows you to run simple web apps at the expense of HF.

References:
- @younesbelkada has made a space with the early version of Petals: https://huggingface.co/spaces/ybelkada/petals/tree/main
- There is another related project that integrates petals 1.0.0, https://huggingface.co/spaces/hivemind-personalized-chat/chat-gradio/tree/main

**Task:** create something similar to chat.petals on top of HF spaces. One way to do this is to fork @younesbelkada 's project and update it to the latest stable version of Petals