Guidance with OpenAI compatible servers

[AntoineBlanot]

Use OpenAI compatible servers A lot of recent frameworks (llama.cpp, vLLM, and other...) make their models available through an OpenAI compatible API. I think it would be awesome if we could use the OpenAI client as the entry point for any models (OpenAI models but also llama.cpp and vLLM models).

I have tried using the OpenAI Engine in guidance with a OpenAI compatible server from llama.cpp but was unable to do it (some tokenizer issues, and even more). This would be an amazing feature and makes integration with other projects easier.