[css-nesting-1][editorial] Fix examples that I broke earlier.

Author: tabatkins

css-nesting-1/Overview.bs

@@ -75,8 +75,8 @@ Motivation</h3>
 			table.colortable {
 				& td {
 					text-align:center;
-					.c { text-transform:uppercase }
-					:first-child, :first-child + td { border:1px solid black }
+					&.c { text-transform:uppercase }
+					&:first-child, &:first-child + td { border:1px solid black }
 				}
 				& th {
 					text-align:center;