`preview-hidden-comments` includes the whole comment in the preview

URL: https://github.com/sindresorhus/refined-github/pull/4520#discussion_r659341139

<img width="712" alt="Screen Shot 4" src="https://user-images.githubusercontent.com/1402241/123726390-156e5100-d8ba-11eb-8a47-77329271c762.png">


Tested in Safari and Chrome