[css-flexbox] Fix markup. #1735

Author: fantasai

css-flexbox/Overview.bs

@@ -2827,7 +2827,7 @@ Flex Container Intrinsic Main Sizes</h4>
 			Add each item’s outer <a>flex base size</a>
 			to the product of its <em>rescaled</em> <a>flex grow factor</a>
 			(or its <em>rescaled</em> <a>flex shrink factor</a>
-			multiplied by its <var>flex base ratio</a>,
+			multiplied by its <var>flex base ratio</var>,
 			if the chosen <var>max-content flex fraction</var> was negative)
 			and the chosen <var>max-content flex fraction</var>,
 			then clamp that resulting item size according to the item’s