minor readme tweaks

step1-05/demo/src/components/TodoFooter.tsx

@@ -3,7 +3,7 @@ import React from 'react';
 export const TodoFooter = (props: any) => {
   return (
     <footer>
-      <p>footer</p>
+      <div>Footer</div>
     </footer>
   );
 };

step1-05/demo/src/components/TodoHeader.tsx

@@ -2,6 +2,10 @@ import React from 'react';
 
 export class TodoHeader extends React.Component {
   render() {
-    return <div>Header</div>;
+    return (
+      <header>
+        <div>Header</div>
+      </header>
+    );
   }
 }

step1-05/demo/src/components/TodoList.tsx

@@ -2,6 +2,10 @@ import React from 'react';
 
 export class TodoList extends React.Component<any, any> {
   render() {
-    return <div />;
+    return (
+      <div>
+        <span>List</span>
+      </div>
+    );
   }
 }