Fix the hello-world template app

apps/template-hello-world/app.ts

@@ -1,7 +1,7 @@
 import application = require("application");
-application.mainModule = "app/main-page";
+application.mainModule = "main-page";
 
 // Remove this in the AppBuilder templates
-application.cssFile = "app/template-hello-world/app.css"
+application.cssFile = "app.css"
 
 application.start();