Scope check

• This is core LLM communication (not application logic)
• This benefits most users (not just my use case)
• This can't be solved in application code with current RubyLLM
• I read the Contributing Guide

Due diligence

• I searched existing issues
• I checked the documentation

What problem does this solve?

There is no integration with Grok from XAI and open ai API is not compatible

Proposed solution

Add xAI API support to RubyLLM

Why this belongs in RubyLLM

xAI support fits in RubyLLM to keep things simple for everyone.

If no one is working on this already I'm happy to open a PR.