src/vs/base/node/pfs.ts/doCopyDirectory
async function doCopyDirectory(source: string, target: string, mode: number, payload: ICopyPayload): Promise<void> {

	// Create folder
	await Promises.mkdir(target, { recursive: true, mode });

	// Copy each file recursively
	const files = await readdir(source);
	for (const file of files) {
		await doCopy(join(source, file), join(target, file), payload);
	}
}