docs: Add docstrings with examples to types

[MarcoGorelli]

What type of PR is this? (check all applicable)

• [ ] 💾 Refactor
• [ ] ✨ Feature
• [ ] 🐛 Bug Fix
• [ ] 🔧 Optimization
• [ ] 📝 Documentation
• [ ] ✅ Test
• [ ] 🐳 Other

Related issues

• Related issue #\<issue number>
• Closes #\<issue number>

Checklist

• [ ] Code follows style guide (ruff)
• [ ] Tests added
• [ ] Documented the changes

If you have comments or can explain your changes, please do so below

[MarcoGorelli]

Marimo CI failure is unrelated, will be fixed by https://github.com/marimo-team/marimo/pull/2947