[css-cascade-5] Cross-reference preshint rules

w3c#6735 (comment)

Author: fantasai

css-cascade-5/Overview.bs

@@ -1018,6 +1018,11 @@ Cascade Sorting Order</h3>
 
 			See [[css-style-attr]].
 
+			Note: Non-CSS presentational hints (such as presentational markup)
+			are handled separately,
+			see [[#preshint]].
+
+
 		<dt id='cascade-layering'>Layers
 		<dd>
 			Declarations within each [=origin=] and [=context=]