Markdown support proof

Markdown support proof keeps MdWrk's product page, renderer package, editor package, and static examples aligned. The public site should not make Markdown claims that are disconnected from package behavior.

The renderer and editor package families are the most important reusable surfaces for Markdown behavior. They let the product, docs, examples, and future integrations rely on a common implementation story.

This proof page is product-specific. The portable lander package only supplies the proof matrix and page rendering shape.