GGUF model format support

[frankiethull]

hello - I have been running local LLMs and small language models for ~ 1 year or so.

One of the features I thought would be useful on the R/chattr side, is support for GGUF model format. Most of the pre-trained models downloadable on huggingface and nomic ai are in GGUF format (phi-2, mistral, etc.).