[css-color-hdr-1] Accept dynamic-range-limit-mix() as a type instead of a literal function

Author: cdoublev

css-color-hdr-1/Overview.bs

@@ -259,7 +259,7 @@ The 'dynamic-range-limit' property {#the-dynamic-range-limit-property}
 
 	<pre class='propdef'>
 		Name: dynamic-range-limit
-		Value: standard | high | constrained-high | ''dynamic-range-limit-mix()''
+		Value: standard | high | constrained-high | <<dynamic-range-limit-mix()>>
 		Initial: high
 		Applies to: all elements
 		Inherited: no