No, the point is that Calibre treats any .txt as if it's in Markdown format, and the link I gave explained the syntax it's expecting, not anything to download. If you want to have your text as you want, you'll need the input to be:
Code:
"Nice day today," said Fred.
"I suppose it is," George replied absent-mindedly.
It does make it easy to add chapters though (just put a "## " before the chapter text, e.g. "## Chapter 1"