[Feature][Agent Onboarding] Add an AGENTS.md file or similar

[ewega]

Search before asking

• [x] I had searched in the issues and found no similar feature requirement.

Use case

As a contributor, I would like my AI tool to automatically be onboarded onto this project

Description

Add an AGENTS.md file (preferred) at the root. This is a tool-agnostic schema for onboarding different AI tools with project context, e.g. GitHub Copilot, Claude Code, Codex. https://agents.md/

Alternatively, GitHub Copilot allows for .github/copilot-instructions file, each tool having their own specific form of definition

Related issues

No response

Are you willing to submit a PR?

• [x] Yes I am willing to submit a PR!

Code of Conduct

• [x] I agree to follow this project's Code of Conduct