code: func (h *HTTPBin) Index(w http.ResponseWriter, r *http.Request) {
  	if r.URL.Path != "/" {
  		http.Error(w, "Not Found", http.StatusNotFound)
  		return
  	}
  	w.Header().Set("Content-Security-Policy", "default-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' camo.githubusercontent.com")
  	writeHTML(w, assets.MustAsset("index.html"), http.StatusOK)
  }
docs: // Index renders an HTML index page