기존 sitemap plugin을 gatsby-plugin-advanced-sitemap로 변경

[je0ngyun]

• 기존 sitemap plugin을 gatsby-plugin-advanced-sitemap로 변경
• robots.txt 생성시 변경된 sitemap주소를 참조하도록 수정
• robots.txt Allow제거

[netlify[bot]]

✅ Deploy Preview for jeongyunlog ready!

Name	Link
🔨 Latest commit	90f22e9afe36778ec9423232a36efc4459aa5b52
🔍 Latest deploy log	https://app.netlify.com/sites/jeongyunlog/deploys/63afee0b3ea3a90008c5cf97
😎 Deploy Preview	https://deploy-preview-6--jeongyunlog.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 settings.