Add tested configuration management to copilot instructions

[Copilot]

This PR adds comprehensive guidance to the copilot instructions for handling issues with the "tested config" label and integrating them into the project documentation.

Overview

The repository receives user-submitted camera configurations through GitHub issues created with the "tested config" template. These configurations are valuable community contributions that should be properly processed and added to the project's documentation website at https://sunoo.github.io/homebridge-camera-ffmpeg/configs/.

Changes

Added a new "Tested Configuration Management" section to .github/copilot-instructions.md that includes:

Processing Workflow

• How to identify issues created with the .github/ISSUE_TEMPLATE/tested_config.md template
• Steps to extract manufacturer/model information and configuration data
• Configuration validation requirements (JSON syntax, required fields, schema compliance)
• Guidelines for sanitizing sensitive information (passwords, tokens, IP addresses)

Documentation Integration

• References to the sunoo.github.io documentation website structure
• Integration points in README.md and config.schema.json
• Issue lifecycle management (issues with "tested config" label are exempt from stale workflow)

Best Practices

• Categorization by camera manufacturer (Hikvision, Dahua, Reolink, etc.)
• Configuration validation against the current plugin schema
• Documentation maintenance and link updates

Context

The existing system already has:

• Issue template for tested configurations that applies the "tested config" label
• Stale workflow exemption for these issues (.github/workflows/stale.yml)
• Documentation website references in README.md and config.schema.json

This PR ensures that copilot agents working on the repository understand how to properly handle these valuable community contributions and integrate them into the project documentation.

Fixes #1512.

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.