Adapts Blankslate to render proportionally in narrow areas

[mperrotti]

Authors: Please fill out this form carefully and completely.

Reviewers: By approving this Pull Request you are approving the code change, as well as its deployment and mitigation plans.
Please read this description carefully. If you feel there is anything unclear or missing, please ask for updates.

What are you trying to accomplish?

Use container queries to adjust the spacing and sizing of the Blankslate component to work well in small areas.

Screenshots

Before:

After:

Integration

No production updates required

List the issues that this change affects.

Relates to https://github.com/github/primer/issues/2678

Risk Assessment

• Low risk the change is small, highly observable, and easily rolled back.
• Medium risk changes that are isolated, reduced in scope or could impact few users. The change will not impact library availability.
• High risk changes are those that could impact customers and SLOs, low or no test coverage, low observability, or slow to rollback.

What approach did you choose and why?

I chose container queries over a new "small" variant because it's very unlikely we'd want large text and a lot of spacing in a Blankslate that's used in a small area.

Anything you want to highlight for special attention from reviewers?

No

Accessibility

• No new axe scan violation - This change does not introduce any new axe scan violations.

Merge checklist

• Added/updated tests
• Added/updated documentation
• Added/updated previews (Lookbook)
• Tested in Chrome
• Tested in Firefox
• Tested in Safari
• Tested in Edge

Take a look at the What we look for in reviews section of the contributing guidelines for more information on how we review PRs.

[changeset-bot]

🦋 Changeset detected

Latest commit: 11e4e20

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@primer/view-components	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[github-actions]

Uh oh! @mperrotti, the image you shared is missing helpful alt text. Check your pull request body.

Alt text is an invisible description that helps screen readers describe images to blind or low-vision users. If you are using markdown to display images, add your alt text inside the brackets of the markdown image.

Learn more about alt text at Basic writing and formatting syntax: images on GitHub Docs.

[github-actions]

⚠️ Visual differences found

Our visual comparison tests found UI differences. Please review the differences by viewing the files changed tab to ensure that the changes were intentional.

Review visual differences

[langermank]

Nice! Just needs a changeset and should be good to merge