[css-syntax] Now that selectors have a CSS grammar, ref that properly…

…. Also switch the remaining <i>s to <a>.

css-syntax/Overview.bs

@@ -3213,27 +3213,27 @@ Defining Arbitrary Contents: the <<declaration-value>> and <<any-value>> product
 CSS stylesheets</h2>
 
 	To <dfn>parse a CSS stylesheet</dfn>,
-	first <i>parse a stylesheet</i>.
-	Interpret all of the resulting top-level <i>qualified rules</i> as <i>style rules</i>, defined below.
+	first <a>parse a stylesheet</a>.
+	Interpret all of the resulting top-level <a>qualified rules</a> as <a>style rules</a>, defined below.
 
 	If any style rule is <a>invalid</a>,
 	or any at-rule is not recognized or is invalid according to its grammar or context,
-	it's a <i>parse error</i>.
+	it's a <a>parse error</a>.
 	Discard that rule.
 
 <h3 id="style-rules">
 Style rules</h3>
 
-	A <dfn>style rule</dfn> is a <i>qualified rule</i>
+	A <dfn>style rule</dfn> is a <a>qualified rule</a>
 	that associates a <a href="https://drafts.csswg.org/selectors4/#selector-list">selector list</a> [[!SELECT]]
 	with a list of property declarations.
 	They are also called
 	<a href="https://www.w3.org/TR/CSS21/syndata.html#rule-sets">rule sets</a> in [[!CSS21]].
 	CSS Cascading and Inheritance [[!CSS3CASCADE]] defines how the declarations inside of style rules participate in the cascade.
 
-	The prelude of the qualified rule is parsed as a
-	<a href="https://drafts.csswg.org/selectors4/#selector-list">selector list</a>.
-	If this results in an <a href="https://drafts.csswg.org/selectors4/#invalid">invalid selector list</a>,
+	The prelude of the qualified rule is <a lt="parse something according to a CSS grammar">parsed</a>
+	as a <<selector-list>>.
+	If this returns failure,
 	the entire style rule is <a>invalid</a>.
 
 	The content of the qualified rule’s block is parsed as a
@@ -3249,7 +3249,7 @@ Style rules</h3>
 
 	Note: The names of Custom Properties [[CSS-VARIABLES]] are case-sensitive.
 
-	<i>Qualified rules</i> at the top-level of a CSS stylesheet are style rules.
+	<a>Qualified rules</a> at the top-level of a CSS stylesheet are style rules.
 	Qualified rules in other contexts may or may not be style rules,
 	as defined by the context.