docs: remove yarn export command references from README

[HagaSpa]

Background / 背景

The yarn export command no longer exists in package.json, but documentation still references it, causing confusion for developers.
yarn exportコマンドはpackage.jsonに存在しませんが、ドキュメントでまだ参照されており、開発者の混乱を招いています。

Changes / 変更内容

• Removed yarn export references from README.md:

  • Changed "Build & Export" section to "Build"
  • Removed yarn export and npm run export commands
  • Updated Available Scripts section to remove yarn export

• Added accurate script references:

  • Added yarn start - Start production server
  • Added yarn lint:text - Run textlint on markdown content

• Clarified that build process automatically includes static export

• README.mdからyarn exportの参照を削除:

  • "Build & Export"セクションを"Build"に変更
  • yarn exportとnpm run exportコマンドを削除
  • Available Scriptsセクションからyarn exportを削除

• 正確なスクリプト参照を追加:

  • yarn start - プロダクションサーバーを開始
  • yarn lint:text - マークダウンコンテンツでtextlintを実行

• ビルドプロセスが自動的に静的エクスポートを含むことを明確化

Impact scope / 影響範囲

Documentation-only changes that align README.md with the actual package.json scripts. No functional changes to the application.

README.mdを実際のpackage.jsonスクリプトと整合させるドキュメントのみの変更。アプリケーションの機能変更はありません。

Testing / 動作確認

• Verified all referenced commands exist in package.json

• Confirmed no broken command references remain

• Checked that documentation accurately reflects current build process

• 参照されているすべてのコマンドがpackage.jsonに存在することを確認

• 壊れたコマンド参照が残っていないことを確認

• ドキュメントが現在のビルドプロセスを正確に反映していることを確認

🤖 Generated with Claude Code

[claude]

Claude finished @HagaSpa's task —— View job

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PR Review Complete ✅

Review Tasks:

• Read the modified README.md file
• Verify command accuracy against package.json
• Check project guidelines in CLAUDE.md
• Analyze changes for documentation quality
• Provide comprehensive review feedback

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📋 Review Summary

This PR effectively removes outdated yarn export command references from the README.md documentation. Overall, this is a high-quality documentation improvement that aligns the README with the actual project setup.

✅ Positive Findings

Accuracy & Correctness:

• All referenced commands in the updated documentation exist in package.json:9-14
• Removal of non-existent yarn export command eliminates developer confusion
• Addition of yarn start and yarn lint:text provides complete script coverage

Documentation Quality:

• Clear, concise explanations that match the project's bilingual approach
• Section restructuring ("Build & Export" → "Build") is more accurate
• Build process clarification helps developers understand the static export is automatic

Consistency with Project Guidelines:

• Follows the conventional commit format defined in CLAUDE.md:95-100
• Aligns with the project's focus on static site generation mentioned in CLAUDE.md:6-7
• Maintains the established documentation style and formatting

📊 Review Categories Assessment

Code Quality & Best Practices: ✅ Excellent

• Documentation follows markdown best practices
• Consistent formatting and structure
• Clear command examples with both yarn and npm alternatives

Potential Bugs/Issues: ✅ None Found

• All commands verified to exist in package.json
• No broken references or incorrect instructions
• Build process accurately described

Performance Considerations: ✅ Not Applicable

• Documentation-only changes with no performance impact

Security Concerns: ✅ None

• No security implications for documentation updates

Test Coverage: ✅ Not Applicable

• Documentation changes don't require test coverage
• However, the PR description shows good testing methodology with verification checkboxes

🎯 Minor Suggestions

1. Consider adding npm equivalents: While yarn start is documented, you might consider showing the npm equivalent (npm start) for consistency with other commands.

2. Development workflow clarification: The updated documentation could benefit from mentioning that yarn build creates the out directory that GitHub Pages serves from (this detail is in CLAUDE.md but might be useful in README).

🏆 Final Assessment

Recommendation: ✅ Approve and Merge

This PR demonstrates excellent documentation maintenance practices:

• Proactively identifies and fixes outdated information
• Improves developer experience by providing accurate commands
• Maintains consistency with project architecture and deployment strategy
• Follows established contribution patterns

The changes are low-risk, high-value improvements that enhance the project's maintainability and developer onboarding experience.

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