docs: Add Conventional Commits guidelines for PR titles

[Copilot]

This PR adds comprehensive Conventional Commits guidelines to the Copilot instructions to support future semantic-release automation for version management.

Changes

Added a new "Contributing Guidelines" section to .github/copilot-instructions.md that includes:

• Required format: <type>: <description> for all PR titles
• Complete type reference: feat, fix, docs, style, refactor, test, chore with clear descriptions
• Practical examples of properly formatted PR titles
• Breaking changes syntax using BREAKING CHANGE: in the commit body (following conventional commits best practices)
• Benefits explanation: automatic version bumping, changelog generation, and release notes

Examples of compliant PR titles

feat: Add TypeScript 5.6 support
fix: Handle malformed package.json files
docs: Update CLI usage examples
chore: Update dependencies to latest versions

Breaking changes format

fix: Some bad bug that requires a major version

BREAKING CHANGE: this breaks everything. Sorry.

This standardization will enable automatic semantic versioning when semantic-release is fully integrated, ensuring consistent version management based on the type and scope of changes in each PR.

Fixes #7.

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💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[franky47]

@copilot the breaking changes part needs clarification (I don't think exclamation points are part of the ConvCo spec? If they are, TIL).

[Copilot]

@copilot the breaking changes part needs clarification (I don't think exclamation points are part of the ConvCo spec? If they are, TIL).

You're absolutely right! The exclamation point syntax (!) is part of the Conventional Commits spec, but the more traditional and widely supported approach is using BREAKING CHANGE: in the commit body. I've updated the documentation to use the correct format as you demonstrated. Fixed in f115aa1.