Updated getting-started.md by mentioning the steps needed to verify c…

…hanges made to composer-playground package. (hyperledger-archives#1879)

* Update getting-started.md

* Update getting-started.md

* Update getting-started.md

contrib-notes/getting-started.md

@@ -79,6 +79,16 @@ You must bootstrap the repository so that all of the dependencies are installed
 You can then work with the packages under [packages/](packages/) on a per-package
 basis as any normal node.js package.
 
+For example, inorder to run Playground UI locally you can run:
+
+    $ npm start
+
+on composer-playground-api and composer-playground packages in turn followed by visiting:
+
+    localhost:3000 
+
+from your browser.
+
 Alternatively, you can execute npm commands across all of the packages at once using
 Lerna: