[Components content]: Default example descriptions for 2025-01

[SteveSill]

Summary

This PR adds new descriptions to the defaultExample of all 36 admin UI components for 2025-01.

What changed

• 36 doc.ts files updated with description fields in defaultExample blocks
• No code, example files, subSections, definitions, or other fields modified
• Descriptions are identical to the approved 2025-07 versions (PR [Components content]: Default example descriptions for 2025-07 #3952), as the example code is identical across these versions

[github-actions]

We detected some changes in packages/*/package.json or packages/*/src, and there are no updates in the .changeset directory. If the changes are user-facing and should cause a version bump, run yarn changeset to track your changes and include them in the next release CHANGELOG. If you are making simple updates to repo configuration, examples, or documentation, you do not need to add a changeset.

[mcvinci]

❤️