clean up step 2-2

playground/src/components/TodoApp.tsx

@@ -6,7 +6,7 @@ import { TodoList } from './TodoList';
 
 export const TodoApp = (props: {}) => (
   <Stack horizontalAlign="center">
-    <Stack style={{ width: 400 }} verticalGap={25}>
+    <Stack style={{ width: 400 }} gap={25}>
       <TodoHeader />
       <TodoList />
       <TodoFooter />

playground/src/components/TodoList.tsx

@@ -23,7 +23,7 @@ class TodoList extends React.Component<TodoListProps> {
     });
 
     return (
-      <Stack verticalGap={10}>
+      <Stack gap={10}>
         {filteredTodos.map(id => (
           <TodoListItem key={id} id={id} />
         ))}