fix readme title

[statefb]

@claude Add "RAPID" after title on readme (both ja and en) like "Review & Assessment Powered by Intelligent Documentation (RAPID)"

[claude]

Claude finished @statefb's task —— View job • claude/issue-28-20250624_075535 • Create PR ➔

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I'll update the README titles to include "RAPID" as requested. Let me work on this:

• Find and identify both README files (English and Japanese versions)
• Update the English README title to include "(RAPID)"
• Update the Japanese README title to include "(RAPID)"
• Commit the changes
• Create a pull request

I've located both README files:

• Main Japanese README: /README.md
• English README: /docs/en/README_en.md

I've updated both README files, adding "(RAPID)" after the title "Review & Assessment Powered by Intelligent Documentation".

Changes have been committed successfully.