code: func (s siteRenderContext) renderSingletonPages() bool {
  	if s.multihost {
  		// 1 per site
  		return s.outIdx == 0
  	}
  
  	// 1 for all sites
  	return s.sitesOutIdx == 0
  
  }
docs: // Whether to render 404.html, robotsTXT.txt which usually is rendered
  // once only in the site root.