Update to latest standard for prompt writing

[yeelam-gordon]

Pull Request Checklist

• I have read and followed the CONTRIBUTING.md guidelines.
• My contribution updated a 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

Fixes #464

According to latest https://code.visualstudio.com/docs/copilot/customization/prompt-files#_prompt-file-format, the existing prompts.instructions.md is just out-dated.
This pull request updates the documentation for creating prompt files, providing clearer and more structured guidance on required YAML frontmatter fields and their usage. The changes aim to make prompt file requirements easier to understand and maintain.

Documentation improvements:

• Replaced the unstructured frontmatter requirements section with a detailed table outlining each field (description, name, agent, model, tools, argument-hint), specifying which are required or recommended, and describing their purpose.
• Added guidelines on quoting, field placement, tool/agent behavior, and preservation of additional metadata to improve consistency and clarity in prompt file creation.

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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

VS Code Prompt Files Documentation

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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 pull request updates the documentation for creating GitHub Copilot prompt files to align with the latest VS Code standards. The changes replace the previous unstructured frontmatter requirements with a detailed table format that clearly defines each field's purpose and requirement level.

Key changes:

• Replaced compressed frontmatter guidance with a structured table listing all available fields (description, name, agent, model, tools, argument-hint)
• Updated field name from mode to agent to match current VS Code documentation and repository conventions
• Added clearer guidelines about field requirements (Required/Recommended/Optional) and default behaviors

[yeelam-gordon]

@aaronpowell and @hizahizi-hizumi, I see you’re the initial approver and author of this file—please take a look. Much appreciated.