## Pull Request Overview

[tasal9]

Pull Request Overview

This PR updates the GitHub Copilot documentation to include support for the new Grok Code Fast 1 model from xAI, which is rolling out in public preview. The changes ensure the documentation accurately reflects the expanded model offerings while maintaining the same data retention and security policies.

Key changes:

• Added Grok Code Fast 1 model to the list of supported xAI models
• Updated all model references to include both Grok models consistently
• Changed singular references to plural for grammatical accuracy

Originally posted by @copilot-pull-request-reviewer in github/docs#40045 (review)