docs: fill type alias API descriptions

[gpbl]

What Changed

• Added JSDoc descriptions for public type aliases that rendered with blank API descriptions.
• Regenerated the version-next API reference so /next/api/react shows descriptions in the Type Aliases table.

Review Notes

No changeset: this is documentation-only and does not change runtime behavior or the public type shape.

Validated with:

• pnpm --filter website generate:api:next
• pnpm --filter react-day-picker typecheck
• git diff --check

[changeset-bot]

⚠️ No Changeset found

Latest commit: 732e90c

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

Name	Type
@daypicker/buddhist	Patch
@daypicker/ethiopic	Patch
@daypicker/hebrew	Patch
@daypicker/hijri	Patch
@daypicker/persian	Patch
react-day-picker	Patch
@daypicker/react	Patch

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