title: Naming convention for const object keys in ES6
body: <p>Is there a recommended naming convention for key names within a const object in es6? I haven't been able to find a resource which states if they should be uppercase or lowercase.</p>
  
  <pre><code>const COLOR_CODES = {
    BLUE: 1,
    RED: 1
  };
  </code></pre>
  
  <p>vs</p>
  
  <pre><code>const COLOR_CODES = {
    blue: 1,
    red: 1
  };
  </code></pre>
  
  <p><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/const" rel="noreferrer">The examples</a> from this MDN article show both styles, so maybe both are acceptable.</p>