Stash's Markdown implementation of paragraph breaks specifically states that Each paragraph begins on a new line. Simply press <return> for a new line.

This is at odds with GFM and Daring Fireball's Markdown, A paragraph is one or more consecutive lines of text, separated by one or more blank lines., which is unexpected.

Translating line breaks into paragraph breaks almost always results in unexpected output--the "impedance mismatch" between fixed-pitch and proportional fonts, combined with the often large discrepancy between the source vs. the rendered characters of hyperlinks results in paragraph breaks that range from slightly off to downright ugly.