Add comprehensive PHP comeback analysis documentation

[Copilot]

This PR adds a detailed analysis document examining PHP's resurgence in modern software development. The document addresses all aspects raised in the issue with comprehensive research and industry data.

What's Included

The new php-comeback-analysis.md document provides:

1. Current State Analysis

• Market position data showing PHP powers 77.5% of websites with known server-side languages
• GitHub activity rankings and job market trends
• Performance improvements with PHP 8.x series including JIT compilation

2. Technical Comeback Drivers

• Modern PHP features like union types, attributes, and match expressions
• Framework ecosystem growth (Laravel, Symfony)
• Developer tooling improvements and package management

3. Language Landscape Analysis

• Which technologies PHP is replacing (legacy ASP, ColdFusion, custom CMS solutions)
• Complementary relationships in modern architectures (PHP + Node.js, microservices)
• Real-world implementation patterns

4. Historical Context

• Detailed analysis of other language comebacks including:
  • JavaScript (2009-2015): From "toy language" to ecosystem dominance
  • Python (2010-2020): Academic to AI/ML powerhouse
  • Rust (2015-Present): Niche to fastest-growing systems language
  • TypeScript, C++, Fortran, and COBOL revival patterns

5. Industry Patterns

• Common factors enabling language comebacks (technical evolution, market timing, community support)
• Enterprise success stories (Slack, Etsy, Wikipedia)
• Future outlook and implications for developers and organizations

Documentation Standards

The document follows the repository's established format with:

• Clear section structure and executive summary
• Practical code examples demonstrating modern PHP features
• Real-world case studies and statistics
• Comprehensive references for further learning
• Professional analysis suitable for the Dev-Journal knowledge base

The README.md has been updated to include the new document under a "Programming Languages & Industry Trends" section, maintaining the repository's organized structure.

Fixes #80.

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