Add copilot-instructions.md and agents.md files for AI development guidance

[Copilot]

This PR adds two essential configuration files to enhance AI-assisted development in the Microsoft Cloud Integrations repository:

Files Added

.github/copilot-instructions.md

A comprehensive GitHub Copilot instructions file that provides:

• Coding practices and standards specific to the repository's technology stack (Angular, TypeScript, Node.js, Azure services)
• Security guidelines for handling Microsoft Cloud services integration
• Code review requirements with focus on performance and security
• Commit message format and pull request guidelines
• Integration patterns for Microsoft Graph, Azure Communication Services, and OpenAI

agents.md

A detailed project documentation file for AI agents and developers containing:

• Complete project structure and architecture overview
• Technology stack documentation (Angular 19+, TypeScript, Docusaurus, Azure services)
• Coding conventions and file naming standards
• Testing protocols with framework requirements (Jest, Angular Testing, Playwright)
• Development environment setup instructions
• Microsoft Cloud services integration guidelines
• Comprehensive contributing guidelines and workflow

Key Features

Both files are tailored specifically to this repository's unique characteristics:

• Integration scenarios across Azure, Microsoft 365, Power Platform, and GitHub
• Sample applications architecture with client/server separation
• Docusaurus-based documentation and tutorials
• Microsoft Graph Toolkit (MGT) usage patterns
• Azure Communication Services implementation

The files follow the template guidelines provided in the issue while being customized for the actual technologies, patterns, and workflows used in this repository. They provide clear guidance for both GitHub Copilot and AI agents on how to work effectively with the codebase.

Fixes #51.

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💡 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.