[css2020] Move cascade 4 to the snapshot proper

Author: frivoal

css-2020/Overview.bs

@@ -184,10 +184,12 @@ Classification of CSS Specifications</h2>
 		<dd>
 			Replaces CSS2&sect;5 and CSS2&sect;6.4.3, defining an extended range of selectors.
 
-		<dt><a href="https://www.w3.org/TR/css3-cascade/">CSS Cascading and Inheritance Level 3</a>
-		  [[!CSS-CASCADE-3]]
+		<dt><a href="https://www.w3.org/TR/css-cascade-4/">CSS Cascading and Inheritance Level 4</a>
+		  [[!CSS-CASCADE-4]]
 		<dd>
-			Replaces CSS2&sect;1.4.3 and CSS2&sect;6
+			Replaces CSS2&sect;1.4.3 and CSS2&sect;6, as well as [[CSS-CASCADE-3]].
+			Describes how to collate style rules and assign values to all properties on all elements.
+			By way of cascading and inheritance, values are propagated for all properties on all elements.
 
 		<dt><a href="https://www.w3.org/TR/css3-values/">CSS Values and Units Level 3</a>
 		  [[!CSS-VALUES-3]]
@@ -274,13 +276,6 @@ Classification of CSS Specifications</h2>
 			which indicates that the element’s subtree is independent of the rest of the page.
 			This enables heavy optimizations by user agents when used well.
 
-		<dt><a href="https://www.w3.org/TR/css-cascade-4/">CSS Cascading and Inheritance Level 4</a>
-		  [[!CSS-CASCADE-4]]
-		<dd>
-			Extends and supersedes [[CSS-CASCADE-3]],
-			describing how to collate style rules and assign values to all properties on all elements.
-			By way of cascading and inheritance, values are propagated for all properties on all elements.
-
 		<dt><a href="https://www.w3.org/TR/css-easing-1/">CSS Easing Functions Level 1</a>
 		  [[!CSS-EASING-1]].
 		<dd>
@@ -750,7 +745,6 @@ Safe to Release pre-CR Exceptions</h2>
 	css-conditional-3,
 	css-namespaces-3,
 	selectors-3,
-	css-cascade-3,
 	css-cascade-4,
 	css-values-3,
 	css-color-3,
@@ -795,7 +789,6 @@ Safe to Release pre-CR Exceptions</h2>
 	css-conditional-3,
 	css-namespaces-3,
 	selectors-3,
-	css-cascade-3,
 	css-cascade-4,
 	css-values-3,
 	css-color-3,
@@ -841,7 +834,6 @@ At-Rule Index</h3>
 	css-conditional-3,
 	css-namespaces-3,
 	selectors-3,
-	css-cascade-3,
 	css-cascade-4,
 	css-values-3,
 	css-color-3,
@@ -886,7 +878,6 @@ At-Rule Index</h3>
 	css-conditional-3,
 	css-namespaces-3,
 	selectors-3,
-	css-cascade-3,
 	css-cascade-4,
 	css-values-3,
 	css-color-3,
@@ -931,7 +922,6 @@ At-Rule Index</h3>
 	css-conditional-3,
 	css-namespaces-3,
 	selectors-3,
-	css-cascade-3,
 	css-cascade-4,
 	css-values-3,
 	css-color-3,