Added a comprehensive agent description for an Expert Vue Frontend Engineer, detailing expertise, approach, guidelines, and code examples.

Pull Request Checklist

• I have read and followed the CONTRIBUTING.md guidelines.
• My contribution adds a new instruction, prompt, or chat mode 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, or chat mode with GitHub Copilot.
• I have run npm start and verified that README.md is up to date.

Description

Added a new vue.js frontend engineering agent

Type of Contribution

• New instruction file.
• New prompt file.
• New chat mode file.
• New collection file.
• Update to existing instruction, prompt, chat mode, or collection.
• Other (please specify):

Additional Notes

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