chore: adds copilot instructions.

[jcchavezs]

We are more often using copilot for reviews and we need to set the instructions to that its catches and suggestions follow our goals and standards.

Thank you for contributing to Coraza WAF, your effort is greatly appreciated
Before submitting check if what you want to add to coraza list meets quality standards before sending pull request. Thanks!

Make sure that you've checked the boxes below before you submit PR:

• My code includes positive and negative tests.
• I have an appropriate description with correct grammar.
• I have read Contribution guidelines, maintainers note and Quality standard.
• My code is properly linted and passes pre-commit tests.

Thanks for your contribution ❤️

[fzipi]

Also, why not using a generic AGENTS.md file in the top directory instead?

[jcchavezs]

Also, why not using a generic AGENTS.md file in the top directory instead?

Not sure agents is suitable for this but I'd go with this first and then see