[css-text-4] Fix refs to property productions (w3c#8565)

Author: cdoublev

css-text-4/Overview.bs

@@ -1734,7 +1734,7 @@ White Space and Wrapping: the 'white-space' property</h2>
 
 	<pre class="propdef">
 	Name: white-space
-	Value: normal | pre | nowrap | pre-wrap | pre-line | <'white-space-collapse'> || <'text-wrap'> || <'text-space-trim'>
+	Value: normal | pre | nowrap | pre-wrap | pre-line | <<'white-space-collapse'>> || <<'text-wrap'>> || <<'text-space-trim'>>
 	Initial: normal
 	Applies to: text
 	Inherited: yes