Expand example for min-/max- shortcoming vs proper range context

A follow-up to w3c#1083 that further expands the example to also include use of high-precision values (while we wait for browsers to support range context queries)

mediaqueries-4/Overview.bs

@@ -735,8 +735,17 @@ Using “min-” and “max-” Prefixes On Range Features</h4>
 		it does not take into account the possibility of fractional viewport sizes which can occur as a result of non-integer pixel densities
 		(e.g. on high-dpi displays or as a result of zooming/scaling).
 		Any viewport widths that fall between 320px and 321px will result in none of the styles being applied.
+
+		One approach to work around this problem is to increase the precision of the values used for the comparison. Using the example above,
+		changing the second comparison value to 320.01px significantly reduces the change that a viewport width on a device would fall
+		between the crack.
+
+		<pre>
+			@media (max-width: 320px) { /* styles for viewports <= 320px */ }
+			@media (min-width: 320.01px) { /* styles for viewports >= 320.01px */ }
+		</pre>
 
-		In these situations, <a>range context</a> queries (which are not limited to “>=” and “<=” comparisons) offer a more appropriate solution:
+		However, in these situations, <a>range context</a> queries (which are not limited to “>=” and “<=” comparisons) offer a more appropriate solution:
 
 		<pre>
 			@media (width <= 320px) { /* styles for viewports <= 320px */ }