}
	var errs []error
	for _, fn := range filenames {
		// Use path.Join for consistency with io/fs pathnames.
		fn = path.Join(mcDir, fn)
		// TODO(jba): check that the file mentions each feature?
		if err := checkFragmentFile(docFS, fn); err != nil {
			errs = append(errs, fmt.Errorf("%s: %v\nSee doc/README.md for more information.", path.Join(docRoot, fn), err))
		}
	}
	return errors.Join(errs...)
}