/**
 * Document → Markdown projection. A best-effort, dependency-free serializer
 * covering the structural nodes and the marks Markdown can represent. Styling
 * marks with no Markdown equivalent (color, background, font family/size) are
 * dropped to plain text; underline/sub/sup fall back to inline HTML, which
 * GitHub-flavored Markdown renders. For loss-free round-trips use getHTML().
 */
import { Node as PMNode } from 'prosemirror-model';
/** Serializes a document node to a Markdown string. */
export declare function docToMarkdown(doc: PMNode): string;