Display item notes in card view if configured

The user can set a maximum length of the item notes to display in each
card. If set to 0, it is hidden.

modules/webapp/src/main/elm/Data/Flags.elm

@@ -16,6 +16,8 @@ type alias Config =
     , docspellAssetPath : String
     , integrationEnabled : Bool
     , fullTextSearchEnabled : Bool
+    , maxPageSize : Int
+    , maxNoteLength : Int
     }