Hiya, this is unfortunately not possible, since linebreaks are not supported.
However you can look at this similar topic for a workaround: Line breaks in command responses
If you don’t like the idea of adding a - (dash) or an _ (underscore) at the end of the line because it’d look ugly, and if you don’t like the idea of having Nightbot sending multiple messages because you want to send everything at once, you can always use the Braille Pattern Blank: ⠀, it looks like a space, but Twitch doesn’t remove them if you type a lot of these, unlike it does for excess of spaces.