docs: simplify youki setup instructions

[bells17]

Description

This PR updates the youki setup instructions on the "Alternative container runtimes" page following the recent update to youki's official documentation.

The youki project recently updated their installation docs. I thought it would be better to point users to the official guide so they can get the latest information directly from the official document.

Related issues or tickets

• https://github.com/youki-dev/youki/pull/3253

Reviews

• [ ] Technical review
• [ ] Editorial review
• [ ] Product review

[netlify[bot]]

✅ Deploy Preview for docsdocker ready!

Name	Link
🔨 Latest commit	dc86c97e3d139cdacaecc6473540e3415c961221
🔍 Latest deploy log	https://app.netlify.com/projects/docsdocker/deploys/68ee3e510c76400008d9e940
😎 Deploy Preview	https://deploy-preview-23550--docsdocker.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 project configuration.