code: async function copyFiles(srcPath: string, destPath: string) {
    return Promise.all(
      walk(srcPath).map(async absoluteSrcFilePath => {
        const relativeFilePath = path.relative(srcPath, absoluteSrcFilePath);
        await copyFile(
          absoluteSrcFilePath,
          path.resolve(destPath, relativeFilePath),
        );
      }),
    );
  }
docs: Copy files (binary included) recursively.