Add skills for contributing commands and localization in VS Code extensions

[alefragnani]

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

Add skills for contributing commands and localization in VS Code extensions.

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Type of Contribution

• New instruction file.
• New prompt file.
• New chat mode file.
• New collection file.
• New skill file.
• Update to existing instruction, prompt, chat mode, collection or skill.
• 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

This PR adds two new skills to help with VS Code extension development: one for contributing commands and another for handling localization. Both skills provide guidelines and best practices for their respective areas.

Changes:

• Added vscode-ext-localization skill for localizing VS Code extensions
• Added vscode-ext-commands skill for contributing commands in VS Code extensions
• Updated docs/README.skills.md to include the two new skills

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 6 comments.

File	Description
skills/vscode-ext-localization/SKILL.md	New skill file providing guidelines for localizing VS Code extensions, covering package.json configurations, walkthrough content, and source code strings
skills/vscode-ext-commands/SKILL.md	New skill file providing guidelines for contributing commands in VS Code extensions, including naming conventions, visibility patterns, and side bar commands
docs/README.skills.md	Updated skill registry to include the two new VS Code extension skills