Read child process I/O

const cmd = new Deno.Command("gum", {
  args: [
    "input",
    "--placeholder=\"Enter your name\"",
  ],
  stdin: "piped",
  stdout: "piped",
  stderr: "piped",
})
const process = cmd.spawn()
Deno.stdin.readable.pipeTo(process.stdin);
process.stdout.pipeTo(Deno.stdout.writable);
process.stderr.pipeTo(Deno.stderr.writable);