title: What is a "declarative format"?
body: <p><a href="http://www.12factor.net/" rel="noreferrer">The Twelve-Factor App</a> says:</p>
  
  <blockquote>
    <p>Use declarative formats for setup automation, to minimize time and cost for new developers joining the project</p>
  </blockquote>
  
  <p>What does "declarative formats" mean?</p>