Add English translation of chapter-09.md for website.en

[Copilot]

This PR creates a complete English translation of chapter-09.md (Team Development Quality Management) for the website.en directory structure.

Overview

The Japanese chapter-09.md file (2,103 lines) has been fully translated to American English and placed in website.en/MarkDown/chapter-09.md (2,110 lines). This chapter covers comprehensive team development quality management practices.

Translation Details

Content Translated:

• 9.1 Effective Code Review Practices - Daily life examples, review mindset guidelines, structured approaches, and automation tools
• 9.2 Establishing and Operating Coding Standards - Naming conventions, method design standards, error handling, and automation
• 9.3 Continuous Integration - CI/CD as quality gates, comprehensive pipeline examples, and quality metrics visualization
• 9.4 Technical Debt Management - Classification systems, repayment strategies, and automation workflows
• 9.5 Use Good Development Tools - Philosophy of tool selection and evaluation criteria
• 9.6 Practical Exercise: Team Quality Improvement Strategies - Phased improvement plans with detailed implementation examples
• 9.7 AI-Era Team Development Strategy - AI pair programming, collaborative processes, knowledge sharing, and modern coding standards
• Chapter summary and conclusion

Quality Assurance:

• All Japanese text translated to American English with proper spelling conventions (e.g., "organization", "analyze", "color")
• Code examples preserved with all comments translated while maintaining syntax integrity
• Image references maintained with correct ../Images/ relative paths (3 image references verified)
• Technical terminology accurately translated for software development context
• File encoded in UTF-8 without BOM as required
• No Japanese characters remaining in the English version

Technical Content:
The translation includes extensive code examples in C#, Java, Python, JavaScript, and YAML, covering modern development practices including AI-assisted development workflows, automated quality gates, and comprehensive team collaboration strategies.

Fixes #185.

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[Copilot]

Pull Request Overview

This PR adds a comprehensive English translation of Chapter 9 (Team Development Quality Management) to the website.en directory, creating a complete 2,110-line English version of the Japanese chapter-09.md file. The translation covers essential team development practices including code reviews, coding standards, continuous integration, technical debt management, and modern AI-era development strategies.

Key changes:

• Complete English translation of all technical content while preserving code examples and formatting
• Translation of all Japanese text to American English with proper spelling conventions
• Maintained all image references and file structure consistency
• Added comprehensive AI-era team development strategies and practical exercises