title: How to get Emmet to generate a custom JSX attribute without quotes
body: <p>I'm trying to remove the quotes generated by Emmet around the <code>props.onInitiateBattle</code> value for custom attribute <code>onClick</code>.</p>
  
  <p><strong>My input</strong> (then CTRL + E to expand, similar to tab):<br />
  <code>button.btn[type="button"][onClick={props.onInitiateBattle}]</code></p>
  
  <p><strong>Emmet's output:</strong><br />
  <code>&lt;button className="btn" type="button" onClick="{props.onInitiateBattle}"&gt;&lt;/button&gt;</code></p>
  
  <p>Notice <code>props.onInitiateBattle</code> WITH quotes, which isn't good.</p>
  
  <p><strong>What I expect</strong> (props... WITHOUT quotes):<br />
  <code>&lt;button className="btn" type="button" onClick={props.onInitiateBattle}&gt;&lt;/button&gt;</code></p>
  
  <p>Wrapping it around double brackets doesn't work either.</p>