adding exercies for steps 2-1 and 2-2

step2-02/exercise/src/index.tsx

@@ -0,0 +1,10 @@
+import React from 'react';
+import ReactDOM from 'react-dom';
+import { TodoApp } from './components/TodoApp';
+import { initializeIcons } from '@uifabric/icons';
+
+// Initializes the UI Fabric icons that we can use
+// Choose one from this list: https://developer.microsoft.com/en-us/fabric#/styles/icons
+initializeIcons();
+
+ReactDOM.render(<TodoApp />, document.getElementById('app'));