code: func CopyLicense(dst, src string) error {
  	files, err := ioutil.ReadDir(src)
  	if err != nil {
  		return err
  	}
  	for _, f := range files {
  		if f.IsDir() {
  			continue
  		}
  		for _, candidate := range licenseFiles {
  			if strings.ToLower(candidate) == strings.TrimSuffix(
  				strings.TrimSuffix(strings.ToLower(f.Name()), ".md"), ".txt") {
  				if err := Copyfile(filepath.Join(dst, f.Name()),
  					filepath.Join(src, f.Name())); err != nil {
  					return err
  				}
  			}
  		}
  	}
  	return nil
  }
docs: // CopyLicense copies the license file from folder src to folder dst.