doc: backpressuring in streams guide

[Bamieh]

In the backpressuring-in-streams guide, this line of text should be updated:

pump is a utility tool that would properly destroy all the streams in a pipeline if one of them fails or closes, and is a must have in this case!

As of node 10, pipeline is introduced to solve this issue, so there is no need to reference an external utility any more 🎉 . I believe the guide should reflect on this new feature providing a small code snippet along with a link to the docs.

const pipeline = util.promisify(stream.pipeline);

async function run() {
  await pipeline(
    fs.createReadStream('archive.tar'),
    zlib.createGzip(),
    fs.createWriteStream('archive.tar.gz')
  );
  console.log('Pipeline succeeded');
}

I am willing to submit a PR if I am on the right track.

Cheers!

@Bamieh：Thanks and I've included the submit. Feel free to submit your ideas.