Features_request: Add Interactive Code Block Features

[Michealjunior]

Describe the feature
Marked.js renders code blocks as static HTML without interactive features. Users need enhanced code blocks with line numbers, copy functionality, and syntax-aware execution. This improvement makes code examples more accessible and functional in documentation and educational content, providing better user experience for developers reading markdown content.

Why is this feature necessary?
Implement interactive code blocks that support toggleable line numbers, one-click copy functionality, language detection with syntax highlighting, and safe code execution sandbox for supported languages. Ensure the implementation is opt-in via a new interactiveCode option, maintains backward compatibility, handles large code blocks efficiently, is fully accessible with keyboard navigation and ARIA labels, and works in all modern browsers. Performance: lazy-load interactive features with no impact on initial page load and memory-efficient handling of multiple code blocks.

Describe alternatives you've considered
New option: interactiveCode: boolean in MarkedOptions interface. CSS classes prefixed with marked-. No external dependencies beyond core browser APIs. Error boundaries for sandboxed execution.

[UziTech]

You can create an extension that does this 😁👍