I'm having a hard time locating the documentation explaining how to add a line break in Doxygen markdown.
I've tried using two spaces at the end of the line, and I've also tried a single or double newline, but none of these are working for me.
I'm using Doxygen version 1.8.9.1.
Put a HTML-break tag <br>
where you want to have a linebreak, does the job.
At least for man page output and HTML output.