[css-fonts-5] Make 100% initial value of size-adjust descriptor. w3c#6110

Author: fantasai

css-fonts-5/Overview.bs

@@ -142,9 +142,9 @@ the 'size-adjust' descriptor</h3>
 
 	<pre class='descdef'>
 	Name: size-adjust
-	Value: normal | <<percentage [0,Infinity]>>
+	Value: <<percentage [0,Infinity]>>
 	For: @font-face
-	Initial: normal
+	Initial: 100%
 	</pre>
 
 	The 'size-adjust' descriptor defines a multiplier