[css-ruby] Add note for ruby font size

Author: kojiishi

css-ruby/Overview.html

@@ -1434,6 +1434,8 @@ <h3 class="no-num heading settled" id=default-ua-ruby><span class=content>
 	<p class=note role=note>Authors should not use the above rules;
 	a UA that supports ruby layout should provide these by default.
 
+	<p class=note role=note>For the use of the <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-fonts-3/#propdef-font-size>font-size</a> property, refer to <a href=#ruby-size>Ruby Annotation Font Size</a>.
+
 <h3 class="no-num heading settled" id=default-inline><span class=content>
 <span class=secno>A.2</span> Inlining Ruby Annotations</span><a class=self-link href=#default-inline></a></h3>
 

css-ruby/Overview.src.html

@@ -1523,6 +1523,9 @@ <h3 id="default-ua-ruby" class="no-num">
 	<p class="note">Authors should not use the above rules;
 	a UA that supports ruby layout should provide these by default.
 
+	<p class="note">For the use of the 'font-size' property,
+		please refer to <a href="#ruby-size">Ruby Annotation Font Size</a>.
+
 <h3 id="default-inline" class="no-num">
 <span class="secno">A.2</span> Inlining Ruby Annotations</h3>