[css-fonts-4] font-weight matching rules for weight=500 are not compatible with level 3

#1061

Author: litherum

css-fonts-4/Overview.bs

@@ -1323,15 +1323,14 @@ at least as dark as its predecessor. Only values between 1 - 999 are valid, and
 		property. If the matching set after performing the steps above includes faces with weight values containing the font-weight desired value, faces with weight values which do not include the desired font-weight value are removed from the matching set. If there is no face which contains the desired value, a weight value is chosen using the rules below:
 		  <ul>
 		    <li>If the desired weight is 400, 400 is checked first, 500 is checked second and then
-		    the rule for desired weights less than 450 is used.</li>
+		    the rule for desired weights less than or equal to 500 is used.</li>
 		    <li>If the desired weight is 500, 500 is checked first, 400 is checked second and then
-		    the rule for desired weights less than 450 is used.</li>
-		    <li>If the desired weight is less than 450, weights below the
+		    the rule for desired weights less than or equal to 500 is used.</li>
+		    <li>If the desired weight is less than or equal to 500, weights below the
 		    desired weight are checked in descending order followed by
 		    weights above the desired weight in ascending order until a
 		    match is found.</li>
-		    <li>If the desired weight is greater than or equal to 450 and not
-		    equal to 500, weights above the
+		    <li>If the desired weight is greater than 500, weights above the
 		    desired weight are checked in ascending order followed by
 		    weights below the desired weight in descending order until a
 		    match is found.</li>