I tried commenting on an answer, and all of my paragraphs were strung together in a single paragraph.

I used proper markdown, adding two spaces at the end of each paragraph.  When that didn't work, I tried appending a `<br/>` to the end of my paragraphs, but that didn't work either!  (In fact, the `<br/>` was rendered in my answer, instead of being interpreted as HTML.)

What was I doing wrong?

If it's relevant, my comment is can be found here: https://apple.stackexchange.com/questions/98080/can-a-macs-model-year-be-determined-with-a-terminal-command/298915#298915