Rename LLM Docs

[DK26]

Renaming files:

LLM_API_REFERENCE.md -> LLM_CONTEXT_FULL.md

• Contains a full mapping and explanation of the API, compressed to be efficient with tokens, and be served as context.

LLM_USER -> LLM_CONTEXT.md

• Contains a "Context7" like format explanation on how to use this crate

Reasoning

Both provide different approaches and could yield different results.
It is expected that LLM_CONTEXT.md file would take less tokens, but will it be as precise as LLM_CONTEXT_FULL.md?

We will see. So I'll keep them both around for users to utilize.