code: def resolve_links(text)
        html = Nokogiri::HTML.fragment(text)
        html.css("a[href]").each do |link|
          href = URI(link["href"])
          next unless href.relative? && markup_for_file(nil, href.path) == :markdown
          link.replace "{file:#{href} #{link.inner_html}}"
        end
        super(html.to_s)
      end
docs: Resolves relative links to Markdown files.
   @param [String] text the HTML fragment in which to resolve links.
   @return [String] HTML with relative links to Markdown files converted to `{file:}` links.