title: onresize event in CodeMirror textarea
body: <p>I want to call a function when user resize the CodeMirror text area. But I can't found a resize event in the event list of CodeMirror <a href="https://codemirror.net/doc/manual.html" rel="nofollow noreferrer">documentation</a>. Are there any method do this. I want to do like below.</p>
  <pre><code>editor.on('resize', function(){
     consolo.log('editor resized');
  });
  </code></pre>