Add blueprint for Live Preview on WordPress.org

[Swanand01]

Summary

This PR adds a blueprint.json file for the plugin. This would enable us to show the Live Preview button for the plugin in the Plugin Directory.

User-facing changes

None.

Testing Instructions

This PR can be tested by following these steps:

1. The blueprint.json file will have to be committed to the plugin’s assets folder, to Subversion.

Reviews

Does this PR have a security-related impact?

No.

Does this PR change what data or activity we track or use?

No.

Does this PR have a legal-related impact?

No.

Checklist

• This PR addresses an existing issue and I have linked this PR to it
• I have tested this code to the best of my abilities
• I have verified accessibility to the best of my abilities (docs)
• I have verified i18n and l10n (translation, right-to-left layout) to the best of my abilities
• This code is covered by automated tests (unit, integration, and/or e2e) to verify it works as intended (docs)
• I have added documentation where necessary
• I have added a matching Type: XYZ label to the PR

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References

• Previews and Blueprints
• Playground

Fixes #13516

[swissspidy]

If this already works, then great!