import type { MarkedExtension } from 'marked';
/**
 * Creates a marked extension that tokenizes footnote references (`[^id]`) and
 * footnote definitions (`[^id]: content`) into custom tokens.
 *
 * The extension produces:
 * - **Inline** `footnoteRef` tokens: `{ type: 'footnoteRef', raw, id }`
 * - **Block** `footnoteSection` tokens: `{ type: 'footnoteSection', raw, footnotes }` where
 *   `footnotes` is an array of `{ id, text }` objects
 *
 * Pair with `FootnoteRef` and `FootnoteSection` components (or your own) for rendering.
 *
 * @example
 * ```svelte
 * <script lang="ts">
 *   import SvelteMarkdown from '@humanspeak/svelte-markdown'
 *   import { markedFootnote, FootnoteRef, FootnoteSection } from '@humanspeak/svelte-markdown/extensions'
 *
 *   const renderers = { footnoteRef: FootnoteRef, footnoteSection: FootnoteSection }
 * </script>
 *
 * <SvelteMarkdown
 *   source={markdown}
 *   extensions={[markedFootnote()]}
 *   {renderers}
 * />
 * ```
 *
 * @returns A `MarkedExtension` with inline `footnoteRef` and block `footnoteSection` tokenizers
 */
export declare function markedFootnote(): MarkedExtension;