Reorder dataset description page to show fields table first

[gmarav05]

• Closes Reorder docs on dataset description page so the fields table is first #357

Changes proposed in this pull request:

• Moved the Dataset description fields table to the top of the page.
• Improves visibility of required fields (e.g., Name) to reduce user confusion.
• Aligns page structure with BIDS dataset_description documentation layout.

This is how it looks after changes.

Screen.Recording.2026-02-22.at.11.32.43.PM.mov

Checklist

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• If an existing page was renamed or deleted, redirects have been added to the mkdocs.yml config

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