[css-flexbox] Address dholbert's wording concerns in https://lists.w3.org/Archives/Public/www-style/2016Apr/0044.html

Author: fantasai

css-flexbox/Overview.bs

@@ -928,11 +928,12 @@ Implied Minimum Size of Flex Items</h3>
 
 			For the purpose of calculating an intrinsic size of the element
 			(e.g. the element's <a>min-content size</a>),
-			this value causes the element's width/height to become indefinite
+			this value causes the element's size in that axis to become indefinite
 			(even if e.g. its 'width' property specifies a <a>definite</a> size).
 			Note this means that percentages calculated against this size
 			will be treated as ''height/auto''.
-			Otherwise, although this may require an additional layout pass to re-resolve percentages in some cases,
+
+			Nonetheless, although this may require an additional layout pass to re-resolve percentages in some cases,
 			this value
 			(like the ''min-content'', ''max-content'', and ''fit-content'' values defined in [[CSS3-SIZING]])
 			does not prevent the resolution of percentage sizes within the item.