code: func matchingFiles(p *regexp.Regexp) []string {
  	var f []string
  	err := filepath.Walk(".", func(path string, fi os.FileInfo, err error) error {
  		if err != nil {
  			return err
  		}
  		n := filepath.Base(path)
  		if !fi.IsDir() && !strings.HasPrefix(n, "zembed_") && p.MatchString(n) {
  			f = append(f, path)
  		}
  		return nil
  	})
  	if err != nil {
  		log.Fatalf("Error walking directory tree: %s", err)
  		return nil
  	}
  	return f
  }
docs: // matchingFiles finds all files matching a regex that should be embedded. This
  // skips files prefixed with "zembed_", since those are an implementation
  // detail of the embedding process itself.