Docs: add workflow for previwing docs site

[yangchuansheng]

🤖 Generated by Copilot at 4a7b37d

Summary

📝🚀🔧

Add a GitHub Actions workflow to preview the documentation site. The workflow file .github/workflows/deploy-docs-preview.yml uses Vercel to deploy a preview of the Sealos documentation site for each pull request and push to the main branch. This allows reviewers and contributors to see the changes in the documentation before merging.

sealos docs site
previewed on Vercel now
autumn leaves falling

Walkthrough

• Add a new workflow file for GitHub Actions that previews the Sealos documentation site on Vercel (link)

[sealos-ci-robot]

🤖 Generated by lychee action

Summary

Status	Count
🔍 Total	956
✅ Successful	375
⏳ Timeouts	0
🔀 Redirected	0
👻 Excluded	580
❓ Unknown	0
🚫 Errors	0

Full action output

Full Github Actions output

[sweep-ai]

Apply Sweep Rules to your PR?

• Apply: Leftover TODOs in the code should be handled.
• Apply: All new business logic should have corresponding unit tests in the tests/ directory.
• Apply: Any clearly inefficient or repeated code should be optimized or refactored.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

📢 Thoughts on this report? Let us know!.