Add missing constructor type to NodeFileTypeParser (#651)

Author: Borewit

index.d.ts

@@ -14,6 +14,8 @@ export type ReadableStreamWithFileType = NodeReadableStream & {
 Extending `FileTypeParser` with Node.js engine specific functions.
 */
 export declare class NodeFileTypeParser extends FileTypeParser {
+	constructor(options?: {customDetectors?: Iterable<Detector>});
+
 	/**
 	@param stream - Node.js `stream.Readable` or web `ReadableStream`.
 	*/