refactor!(config): remove route.extensions

[SoonIter]

Summary

Related Issue

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).

[netlify]

✅ Deploy Preview for rspress-v2 ready!

Name	Link
🔨 Latest commit	d07daa0
🔍 Latest deploy log	https://app.netlify.com/sites/rspress-v2/deploys/6810d7920b66d100088728ad
😎 Deploy Preview	https://deploy-preview-2102--rspress-v2.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[netlify]

✅ Deploy Preview for rspress ready!

Name	Link
🔨 Latest commit	d07daa0
🔍 Latest deploy log	https://app.netlify.com/sites/rspress/deploys/6810d791b44ba500080152fd
😎 Deploy Preview	https://deploy-preview-2102--rspress.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.
Lighthouse	1 paths audited Performance: 81 (🔴 down 11 from production) Accessibility: 97 (no change from production) Best Practices: 92 (🟢 up 9 from production) SEO: 100 (no change from production) PWA: - View the detailed breakdown and full score reports

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[SoonIter]

aligned with docusaurus

https://docusaurus.io/docs/markdown-features/react#importing-markdown

should ignore the _ prefix