title: Pre and post build steps in nx.dev
body: <p>I'm using <strong>nx.dev</strong> to build and test a web application.
  The <code>workspace.json</code> contains the scripts to build and test the app, however the build phase still need a pre processing of some files.</p>
  
  <p>Is there any way of adding a pre build step (i.e. specify an external bash script or JavaScript code)?</p>
  
  <p>The online documentation doesn't mention that 
  <a href="https://nx.dev/react/cli/build" rel="noreferrer">https://nx.dev/react/cli/build</a></p>