title: serve -s build specify port number
body: <p>I'm trying to serve a react-app's build folder from a DigitalOcean droplet. </p>
  
  <p>After I run <code>yarn build</code>, I get told by the script to run </p>
  
  <p><code>yarn global add serve
  serve -s build
  </code></p>
  
  <p>However, when I run <code>serve -s build</code>, It say's it's running on <a href="http://localhost:5000" rel="noreferrer">http://localhost:5000</a>. I would like it run on localhost:3000 instead, as I have another server running on port 5000. How can i specify the port number such that <code>serve -s build</code> runs on port 3000? </p>