Adds overview front matter.

eed3si9n · eed3si9n · commit f7a02f193395 · 2012-11-08T00:00:51.000-05:00
diff --git a/ja/overviews/core/value-classes.md b/ja/overviews/core/value-classes.md
@@ -3,6 +3,7 @@ layout: overview
 label-color: success
 label-text: New in 2.10
 language: ja
+overview: value-classes
 title: 値クラスと汎用トレイト
 ---
 
