message: fix(preview-html): classlist null when devtool open - storybook
  When the storybook is already open with devtool open and the storybook is restarted, will result in
  classlist being null error in console, because of DOM being not loaded
diff: <script data-id="chakra-ui-no-flash">
  ;(function () {
  + window.addEventListener("DOMContentLoaded", function (e) {
  var storageKey = "chakra-ui-color-mode"
  var classNameDark = "chakra-ui-dark"
  var classNameLight = "chakra-ui-light"
  function setClassOnDocumentBody(darkMode) {
  document.body.classList.add(darkMode ? classNameDark : classNameLight)
  - document.body.classList.remove(darkMode ? classNameLight : classNameDark)
  + document.body.classList.remove(
  + darkMode ? classNameLight : classNameDark,
  + )
  }
  var preferDarkQuery = "(prefers-color-scheme: dark)"
  var isDarkMode = document.body.classList.contains(classNameDark)
  localStorage.setItem(storageKey, JSON.stringify(isDarkMode))
  }
  + })
  })()
  </script>
  