[css-syntax] Kill the quoted-url branch from the url-token railroad. Fold the old unquoted-url diagram into url-token.

Author: tabatkins

css-syntax/Overview.bs

@@ -625,22 +625,12 @@ Token Railroad Diagrams</h3>
 			N: <ident-token "url">
 			T: (
 			N: ws*
-			Opt:
-				Seq:
-					Choice:
-						N: url-unquoted
-						N: <string-token>
-					N: ws*
-			T: )
-			</pre>
-
-		<dt id="url-unquoted-diagram">url-unquoted
-		<dd>
-			<pre class='railroad'>
-			Plus:
+			Star:
 				Choice:
-					N: not " ' ( ) \ whitespace or non-printable
+					N: not " ' ( ) \ ws or non-printable
 					N: escape
+			N: ws*
+			T: )
 			</pre>
 
 		<dt id="number-token-diagram"><<number-token>>