docs: added coming soon section to popover docs

[hellogreg]

What I did

1. Added a "Coming soon" section to the top of the docs overview.

Testing Instructions

1. Go to the DP popover page.
2. Verify that it has a "Coming soon" section with info that the element is not yet available.

[changeset-bot]

⚠️ No Changeset found

Latest commit: cddda6a

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

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[github-actions]

Size Change: 0 B

Total Size: 250 kB

ℹ️ View Unchanged

Filename	Size
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./elements/rh-accordion/rh-accordion-header.js	3.74 kB
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_{compressed-size-action}

[markcaron]

Low-key Good Thinking, Man