FIX an issue when re-rendering lit-html elements after rendering a non-lit-html element
FIX an issue when re-rendering lit-html elements after rendering a non-lit-html element

It seems the mountNode becomes stateful after a render has occurred in lit-html.
Since storybook is changing the dom beyond lit-html, it gets "confused" and throws an error because it's unable to remove
some nodes. I guess it's trying to do reconciliation or cleanup, and it's missing state or it's state is inconsistent
with the actual dom.

By adding a extra inner root node that gets reset when switching stories we make lit-html mount correctly

storybooks/react-storybook,storybooks/storybook,storybooks/react-storybook,kadirahq/react-storybook,storybooks/storybook,storybooks/storybook,storybooks/storybook,storybooks/storybook,storybooks/react-storybook,storybooks/storybook,storybooks/storybook,kadirahq/react-storybook,storybooks/react-storybook