LLM 0.32a0 is a major backwards-compatible refactor

LLM 0.32a0 is an alpha release that redesigns how the LLM Python library handles inputs and outputs to better support modern AI models. Instead of the old simple text-in, text-out model, it now represents conversations as sequences of messages (with user and assistant roles) and allows responses to contain different types of content, making it easier to work with APIs like OpenAI's chat completions.