Added Angular CLI pre-requisite for completed project

Author: jasonjoh

demos/03-add-msgraph/README.md

@@ -5,6 +5,7 @@
 To run the completed project in this folder, you need the following:
 
 - [Node.js](https://nodejs.org) installed on your development machine. If you do not have Node.js, visit the previous link for download options. (**Note:** This tutorial was written with Node version 10.7.0. The steps in this guide may work with other versions, but that has not been tested.)
+- [Angular CLI](https://cli.angular.io/) installed on your development machine.
 - Either a personal Microsoft account with a mailbox on Outlook.com, or a Microsoft work or school account.
 
 If you don't have a Microsoft account, there are a couple of options to get a free account: