Clarify simple block value description

Author: jonathantneal

css-syntax-3/Overview.bs

@@ -2599,7 +2599,7 @@ Consume a simple block</h4>
 	(E.g. if it was called with <a href="#tokendef-open-square">&lt;[-token></a>, the <a>ending token</a> is <a href="#tokendef-close-square">&lt;]-token></a>.)
 
 	Create a <a>simple block</a> with its associated token set to the <a>current input token</a>
-	and with a value with is initially an empty list.
+	and with its value initially set to an empty list.
 
 	Repeatedly consume the <a>next input token</a> and process it as follows: