When writing in gist, and using mark down mode, we need to enter a blank line between two lines if we want to break a line (add a new line).
Is it possible to break a line without the need of a space (blank line between them)?
As Ryan said, in markdown the most conventional way of creating a linebreak is by adding two spaces at the end of a line. Though GFM also supports the use of basic HTML blocks, so <br> can also be used to create linebreaks, which can be helpful where multiple linebreaks are needed.