title: What does yarn --pnp?
body: <p>There is this new shining Yarn feature called Plug'n'Play.</p>
  
  <p>I would like to know what it does exactly?</p>
  
  <p>I know it's creating a <code>.pnp</code> folder and a <code>.pnp.js</code> file, but does it change anything else on the machine, like a config file somewhere?</p>
  
  <p>Thank you.</p>