[css-cascade-5] Clarify the behavior of @layers shorthand

Author: mirisuzanne

css-cascade-5/Overview.bs

@@ -1318,7 +1318,7 @@ Un-Named Layers</h5>
 	Issue(w3c/csswg-drafts#5792): Should unnamed cascade layers be allowed?
 
 <h4 id="at-layers">
-Layer-Ordering Shorthand: the ''@layers'' rule</h3>
+Layer-Declaring Shorthand: the ''@layers'' rule</h3>
 
 	The <dfn at-rule id="at-ruledef-layers">@layers</dfn> rule
 	describes a list of explicit [=cascade layers=],
@@ -1330,7 +1330,7 @@ Layer-Ordering Shorthand: the ''@layers'' rule</h3>
 	</pre>
 
 	This is provided as a shorthand for establishing the order of named layers,
-	and otherwise has the same effect as declaring each [=layer name=]
+	and has the same effect as declaring each [=layer name=]
 	in order in its own empty ''@layer'' rule.
 
 	<div class="example">