Updating example for how to run examples

CONTRIBUTING.md

@@ -38,9 +38,8 @@ Examples are included in part to allow manual testing.
 Running example
 
 ```bash
-$ npm install -g http-server
-$ http-server
-# Open 127.0.0.1:8080/example
+$ npm run examples
+# Open 127.0.0.1:3000
 ```
 
 Running sandbox in browser
@@ -55,4 +54,4 @@ Running sandbox in terminal
 ```bash
 $ npm start
 $ node ./sandbox/client
-```
\ No newline at end of file
+```