✨ Set up Copilot instructions for ddev-php8.5 repository

[Copilot]

This PR implements comprehensive Copilot instructions for the ddev-php8.5 repository as requested in the issue. The instructions provide essential context and guidance for AI assistants working with this DDEV add-on repository.

What's Added

Created .github/copilot-instructions.md with comprehensive documentation covering:

Repository Context

• Clear overview of the ddev-php8.5 add-on purpose and current development state
• Reference to general DDEV agent instructions at https://github.com/ddev/.github/AGENTS.md
• Explanation that this is currently template-based and needs PHP 8.5 customization
• Guidance on DDEV's role as a Docker-based local development environment tool

Test Environment Requirements

• Documentation that tests require access to *.ddev.site domains for proper functionality
• Explanation of how DDEV creates local development environments using .ddev.site TLD
• Documentation that permissions need to be lifted to allow apt-get instructions to work in Dockerfiles

Development Guidance

• File Structure: Detailed explanation of key components (install.yaml, Docker Compose files, test suite)
• DDEV Integration: Specific guidance on environment variables, service conventions, and add-on structure
• Testing Framework: Information about the Bats testing setup and validation procedures
• Implementation Roadmap: Clear checklist of tasks needed to complete the PHP 8.5 add-on

Workflow Best Practices

• Contributing guidelines for future developers
• Code style and standards for DDEV add-ons
• Release process and maintenance procedures
• Troubleshooting common issues

Resources and References

• Links to DDEV documentation, add-on development guides, and testing frameworks
• PHP 8.5 specific resources and release notes

Why This Matters

The instructions help AI assistants understand that this repository is currently in early development, based on the DDEV add-on template, and needs specific customization for PHP 8.5 support. This context enables more accurate and helpful assistance with:

• Template customization (renaming files, updating references)
• PHP 8.5 specific configuration
• DDEV ecosystem conventions
• Testing and validation procedures

Technical Details

The instructions follow GitHub's best practices for Copilot coding agents, providing structured information that helps AI understand the repository's purpose, current state, and development requirements. They also reference the general DDEV agent guidelines and document the specific requirements for *.ddev.site access during testing and apt-get permissions for Dockerfile builds. This enables more effective collaboration between developers and AI assistants when working on the PHP 8.5 add-on implementation.

Fixes #3

Original prompt

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This section details on the original issue you should resolve

<issue_title>✨ Set up Copilot instructions</issue_title>
<issue_description>Configure instructions for this repository as documented in Best practices for Copilot coding agent in your repository.

• The key thing is to mention/require the DDEV org-level AGENTS.md from https://github.com/ddev/.github/blob/main/AGENTS.md
• In addition, allow access to *.ddev.site</issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes #3

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✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[rfay]

The two ost important things to do here after repo overview are:

• Reference the general instructions in https://github.com/ddev/.github/AGENTS.md
• Allow access to *.ddev.site for tests

[Copilot]

Added reference to general DDEV agent instructions (https://github.com/ddev/.github/blob/main/AGENTS.md) and documented the requirement for *.ddev.site access for tests in commit 6400a05.

[rfay]

@copilot address the requested changes

[rfay]

@copilot permissions also need to be lifted to allow apt-get instructions to work in the Dockerfile.

[Copilot]

@copilot address the requested changes

Addressed both requested changes in commit 6400a05:

1. Added reference to general DDEV agent instructions
2. Documented *.ddev.site access requirement for tests

[Copilot]

@copilot permissions also need to be lifted to allow apt-get instructions to work in the Dockerfile.

Added the apt-get permissions requirement to the Test Environment Requirements section in commit 2447a40. This documents that permissions need to be lifted to allow apt-get instructions to work in Dockerfiles when building custom PHP 8.5 images.