Add CONTRIBUTING.md file with comprehensive contribution guidelines

[Copilot]

Summary

This PR adds a comprehensive CONTRIBUTING.md file to the repository as requested in issue #XX.

What's Added

The new CONTRIBUTING.md file provides clear guidance for contributors including:

• Getting Started - Prerequisites and initial steps for new contributors
• Development Setup - Detailed setup instructions for the Next.js application, including:
  • Required dependencies (Node.js, npm/yarn)
  • Step-by-step clone and installation process
  • How to run the development server
• How to Contribute - Guidelines for:
  • Reporting bugs with detailed information requirements
  • Suggesting enhancements
  • Contributing code changes with proper branching strategy
• Pull Request Process - Clear workflow from creation to merge
• Code Standards - Best practices for JavaScript/React development
• Testing - Instructions for building and testing changes locally
• Code of Conduct - Community participation guidelines

Key Features

• Proper links to project documentation in the with-strict-csp-app directory
• Markdown formatting with table of contents for easy navigation
• Specific instructions tailored to this Next.js application
• Standard contribution workflow that aligns with GitHub best practices

This contribution guide will help streamline the contribution process and ensure consistency across all contributions to the project.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Please add a contribution.md file</issue_title>
<issue_description>Please create a contribution file

---

💡 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.