docs: add examples

[Barbapapazes]

🔗 Linked issue

related to #219

❓ Type of change

• 📖 Documentation (updates to the documentation, readme, or JSdoc annotations)
• 🐞 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

I create a lot of simple examples to show how to use unbuild.

For untyped, I think there is a bug, see #333
For mkdist, there is a type issue, see #332

For transpiling json or html to esm, there is an error when also having an index.ts file. I do not know if this is a bug or if I am doing something wrong.

I could also add an example for inlining deps?

📝 Checklist

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

[pi0]

Thanks (and sorry for all delays).

In order to iterate I've simplified examples into 3: zero config, mkdist and untyped