This pull request introduces several improvements to the documentation system, focusing on enhanced Markdown rendering, media file management, and support for Mermaid diagrams. The changes ensure that documentation articles can include rich diagrams and images, and that all media assets are properly handled and referenced. Additionally, the build process now automatically copies media files for use in the public site.

• Implements support for relative images in article Markdown files
• Implements support for relative hyperlink between Markdown articles
• Implements Mermaid diagram support in Markdown

• Depends on Implement Markdown reference renderer #19