fix(ci): format README and align markdown tooling with Prettier

[gaomeng1900]

What

Fixes the main-branch CI failure caused by Prettier formatting in README files, removes unused VS Code markdownlint config, and adds *.md to lint-staged so markdown is formatted on commit.

Type

• Breaking change
• Bug fix
• Feature / Improvement
• Refactor / Chores
• Documentation / Website / Demo / Testing

Testing

• Tested in modern browsers
• No console errors
• Types/doc added

Automated validation run locally:

• npx prettier --check . — pass
• npm run lint — pass

Requirements / 要求

• I have read and follow the Code of Conduct and Contributing Guide . / 我已阅读并遵守行为准则。
• This PR is NOT generated by a bot or AI agent acting autonomously. I have authored or meaningfully reviewed every change. / 此 PR 不是由 bot 或 AI 自主生成的，我已亲自编写或充分审查了每一处变更。