feat(cli): add llms.txt

[james-rl]

Description

• Adds llms.txt to improve external agent ability to use the tool in this repo.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Code refactoring
• Performance improvement
• Test updates

Related Issues

Closes #

• This is one part of a larger effort to improve llm performance on our repo

Changes Made

Testing

• I have tested locally
• I have added/updated tests
• All existing tests pass

Checklist

• My code follows the code style of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have updated the documentation accordingly
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published

Screenshots (if applicable)

Additional Notes