add "add double faced card" menu option

data/ch-t.mse-locale/locale

@@ -54,6 +54,8 @@ menu:
 	next card:							選擇下一張卡牌	PgDn
 	search cards:						搜尋卡	Ctrl+K
 	add card:							添加卡牌	Ctrl+Enter
+	#TODO: Localize
+	add card double:					&Add Double Faced Card	Ctrl+Shift+Enter
 	add cards:							批量添加卡牌...
 	remove card:						刪除所選卡牌
 	#TODO: Localize
@@ -208,6 +210,8 @@ help:
 	next card:							選擇列表中的下一張卡牌
 	search cards:						使用搜尋字詞過濾卡片列表
 	add card:							添加一個新的空白卡牌到本套牌
+	#TODO: Localize
+	add card double:					Add a new, blank, card that has a back face to this set
 	add cards:							添加多張卡牌到本套牌
 	remove card:						從本套牌中刪除所選卡牌
 	#TODO: Localize
@@ -466,6 +470,8 @@ tooltip:
 
 	# cards toolbar
 	add card:							添加卡牌
+	#TODO: Localize
+	add card double:					Add double faced card
 	remove card:						移除選中卡牌
 	#TODO: Localize
 	link card:							Link cards to selected card