fix vue3 instructions to use vitest instead of jest

[jaxn]

jest is not supported with vite.

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.

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Description

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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):

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Additional Notes

The Vue3 instructions suggest using Jest with Vite, which is not officially supported by jest and is inconsistent with the other guidelines in the file.

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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

This PR corrects the testing framework recommendation in the Vue 3 instructions file from Jest to Vitest. Since Vue 3 projects typically use Vite as the build tool (as specified in line 14 of the same file), Vitest is the appropriate testing framework choice due to its native integration with Vite. Jest does not have official Vite support, making this change both technically accurate and consistent with other Vite-based framework instructions in the repository.

Key Changes:

• Updated testing section to recommend Vitest instead of Jest for unit testing with Vue Test Utils