[css-color-4][css-color-5][editorial] WPT update

Author: svgeesus

css-color-4/Overview.bs

@@ -5115,6 +5115,10 @@ CSS Gamut Mapping to an RGB Destination</h3>
 	It implements a relative colorimetric intent,
 	and colors inside the destination gamut are unchanged.
 
+	<wpt>
+		parsing/gamut-mapping.html
+	</wpt>
+
 	Note: other situations,
 	in particular mapping to printer gamuts
 	where the maximum black level is significantly above zero,

css-color-5/Overview.bs

@@ -246,6 +246,7 @@ After normalizing both percentages, the result is produced via the following alg
 	parsing/color-computed-color-mix-function.html
 	parsing/color-invalid-color-mix-function.html
 	parsing/color-valid-color-mix-function.html
+	parsing/gamut-mapping.html
 </wpt>
 
 The result of mixing is the color at the specified percentage along the progression
@@ -1078,7 +1079,7 @@ Relative sRGB color syntax is <em>only</em> applicable to the non-legacy RGB syn
 
 <h3 id="relative-HSL">Relative HSL Colors</h3>
 
-The grammar of the ''hsl()'' and ''hsla()'' functions is extended as follows:
+The grammar of the [=modern color syntax=] ''hsl()'' and ''hsla()'' functions is extended as follows:
 
 <pre class='prod'>
 <dfn>hsl()</dfn> = hsl([from <<color>>]?