code: func (b Files) configMaybe(configSet config.Set, path string, metaOnly bool) *config.Config {
  	if body, ok := b[path]; ok {
  		cfg := &config.Config{
  			Meta: config.Meta{
  				ConfigSet:   configSet,
  				Path:        path,
  				ContentHash: hash(body),
  				Revision:    b.rev(),
  				ViewURL:     fmt.Sprintf("https://example.com/view/here/%s", path),
  			},
  		}
  		if !metaOnly {
  			cfg.Content = body
  		}
  		return cfg
  	}
  	return nil
  }
docs: // configMaybe returns config.Config if such config is in the set, else nil.