feat: create learn landing

[Barbapapazes]

🔗 Linked issue

❓ Type of change

• 📖 Documentation (updates to the documentation, readme, or JSdoc annotations)
• 📰 Content (a new article or a change in the content folder)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

Create the landing page for the futur learning content.

• Add /learn/articles
• Add /learn/[...slug]
• Create illustration

We will start by adding Getting Started and Building Blocks. Then, depending of the contents, we will add more topics.

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.

[nuxt-studio]

✅ Live Preview ready!

Name	Edit	Preview	Latest Commit
unjs-website	Edit on Studio ↗︎	View Live Preview	f890398

[Barbapapazes]

Merge this PR under a flag to avoid complexe merge and to finish writing articles