Add Figma plugin information to external.json

[siminapasat]

Added Figma plugin details including name, description, version, author, homepage, keywords, license, repository, and source.

Pull Request Checklist

• I have read and followed the CONTRIBUTING.md guidelines.
• I have read and followed the Guidance for submissions involving paid services.
• My contribution adds a new instruction, prompt, agent, skill, or workflow file in the correct directory.
• The file follows the required naming convention.
• The content is clearly structured and follows the example format.
• I have tested my instructions, prompt, agent, skill, or workflow with GitHub Copilot.
• I have run npm start and verified that README.md is up to date.
• I am targeting the staged branch for this pull request.

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Description

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Type of Contribution

• New instruction file.
• New prompt file.
• New agent file.
• New plugin.
• New skill file.
• New agentic workflow.
• Update to existing instruction, prompt, agent, plugin, skill, or workflow.
• Other (please specify):

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Additional Notes

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By submitting this pull request, I confirm that my contribution abides by the Code of Conduct and will be licensed under the MIT License.

[Copilot]

Pull request overview

Adds a new external plugin entry for a Figma MCP-related plugin to the repository’s external plugin registry (plugins/external.json) so it can be merged into generated marketplace/website data during builds.

Changes:

• Appended a new figma entry to plugins/external.json with metadata (author, homepage, keywords, repository, source).
• Updated the preceding entry to include a trailing comma to keep the JSON array valid after appending.