title: Does docker-compose support init container?
body: <p><code>init container</code> is a great feature in Kubernetes and I wonder whether docker-compose supports it? it allows me to run some command before launch the main application.</p>
  <p>I come cross this PR <a href="https://github.com/docker/compose-cli/issues/1499" rel="noreferrer">https://github.com/docker/compose-cli/issues/1499</a> which mentions to support init container. But I can't find related doc in their reference.</p>