set comments option to a suitable value

Set comments to the same as CSS. This avoids a ">" leader being added when pressing enter at the end of a line starting with >, as in

	ul.special {
		> li {
			color: red;
		}
	}

Before this patch pressing enter at the end of the > li { line annoyingly puts a > at the start of the next line.
Merge pull request #24 from tremby/comments

Set comments option to a suitable value