Add support for GGUF

[FlatlinerDOA]

Proposal

Incorporate the ability to load GPT2 models (and others in future) from the GGUF format as defined here:
https://github.com/ggerganov/ggml/blob/master/docs/gguf.md

There is a fairly approachable library written in TypeScript that could be a good basis:
https://github.com/ahoylabs/gguf.js

Benefits

• Allows loading of models from a single file.
• Easy extensibility for new model support such as Llama2 models in the future.