Fix excess scrolling in mobile

Something was trailing off the screen area causing the app to scroll
away.

www/src/Pages/DeckEditor.elm

@@ -76,6 +76,7 @@ groups cards =
         isEmpty : Group -> Bool
         isEmpty group =
             List.isEmpty group.cards
+
         gather : String -> String -> Group
         gather groupName typeName =
             List.filter (isA typeName) cards
@@ -169,6 +170,7 @@ view model =
     E.column
         [ E.width E.fill
         , E.height E.fill
+        , E.clipX
         ]
         [ case model.deck of
             Ready deck ->