docs: fix step show selected rows in Data-table component

[Lol1chw]

🔗 Linked issue

❓ 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

Changed the documentation for the Data-table component to improve DX.

Continuation of the step-by-step guide to creating a table using different APIs

📸 Screenshots (if appropriate)

📝 Checklist

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

[sadeghbarati]

Can you share an image or video about the PR changes, thanks

[Lol1chw]

Sure, here's the video:
https://github.com/radix-vue/shadcn-vue/assets/94941930/6b940ab4-1803-4e42-9871-11275db3520a

[sadeghbarati]

https://www.material-react-table.com/docs/examples/expanding-tree

I was expecting something like this chevron/arrow icon in the first column to expand the row, but this is a nice usecase too