Adding Shadcn UI to Github Explore topic

[officialrajdeepsingh]

Please confirm this pull request meets the following requirements:

• I followed the contributing guidelines: https://github.com/github/explore/blob/main/CONTRIBUTING.md.
• I am not the sole author or employee of a company who created either the topic I am modifying/adding or the collection entry I am modifying/adding.

Which change are you proposing?

• Suggesting edits to an existing topic or collection
• Curating a new topic or collection
• Something that does not neatly fit into the binary options above

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Curating a new topic or collection

• I've formatted my changes as a new folder directory, named for the topic or collection as it appears in the URL on GitHub (e.g. https://github.com/topics/[NAME] or https://github.com/collections/[NAME])
• My folder contains a *.png image (if applicable) and index.md
• All required fields in my index.md conform to the Style Guide and API docs: https://github.com/github/explore/tree/main/docs

I added shadcn/ui to the GitHub Explore repository because it's a powerful, popular, and developer-friendly React component library that offers fully customizable and accessible UI components using Tailwind CSS and Radix UI, making it a great resource for modern web development.

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Please note: we will close your PR without comment if you do not check the boxes above and provide ALL requested information.

[Copilot]

Pull Request Overview

This pull request adds a new topic "shadcn-ui" to the GitHub Explore repository. It introduces a new folder containing an index.md file and associated metadata for the shadcn/ui topic.

• Added a new metadata file with details such as aliases, display name, description, URLs, and related topics.
• Provides comprehensive information on shadcn/ui to enhance discoverability in GitHub Explore.

[tomthorogood]

@officialrajdeepsingh Thank you for your contribution! It looks like there is one linter request in the test that's failing. If you could please take care of that, we can get this merged in! ❤️