code: func initCMDGroup(router *httprouter.Router) {
  	cmdch := make(chan string, 10)
  	addconnch := make(chan *cmdConn, 10)
  	delconnch := make(chan *cmdConn, 10)
  
  	go cmder(cmdch, addconnch, delconnch)
  
  	router.GET("/_/cmd/ws/*cmd", func(w http.ResponseWriter,
  		r *http.Request, ps httprouter.Params) {
  		cmdch <- ps.ByName("cmd")[1:]
  		w.WriteHeader(http.StatusOK)
  	})
  	router.Handler("GET", "/_/cmd/ws", w.Handler(func(wsc *w.Conn) {
  		respch := make(chan bool)
  		conn := &cmdConn{ws: wsc, respch: respch}
  		addconnch <- conn
  		<-respch
  		delconnch <- conn
  	}))
  }
docs: // initCMDGroup establishes routes for automatically reloading the page on any
  // assets/ change when a watcher is running (see cmd/*watcher.sh).