add specific instructions for angular cli

Author: Karthik Kumar A

README.md

@@ -104,6 +104,14 @@ class MyComponent {
 ```
 
 3. Apart from that, in order to have usable tree in the browser, you need to add **ng2-tree styles** which you can find in your `node_modules/ng2-tree/styles.css`
+In .angular-cli.json, it would be:
+
+```typescript
+      "styles": [
+        "styles.css",
+        "../node_modules/ng2-tree/styles.css",
+      ],
+```
 4. And finally, I suppose, you'd want to listen to events generated by ng2-tree (for a full list of supported events look at the [API](#wrench-api)). No problem, this is also easy to do - for example let's add a listener for `node was selected` kind of events:
 
 ```typescript