Remove chinese/taiwanese Readmes and git-ignore Roadmap

[eighttrigrams]

• We don't know what these Readmes say and can't maintain them
• The Roadmap gitignore allows me to update the Roadmap right inside the project folder

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[Copilot]

Pull request overview

Removes the Simplified Chinese and Traditional Chinese README files from the repository to avoid maintaining content the team can’t verify.

Changes:

• Deleted README.zh-cn.md (Simplified Chinese README)
• Deleted README.zh-tw.md (Traditional Chinese README)

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated no comments.

File	Description
README.zh-cn.md	Removes the Simplified Chinese README from the repo to eliminate unmaintained documentation.
README.zh-tw.md	Removes the Traditional Chinese README from the repo to eliminate unmaintained documentation.

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[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

View in Devin Review to see 3 additional findings.