Creating the controller layer barrel

To finish up our controller layer, we should also create a barrel for it. By now, you should be used to this:

1. Create an index.ts file in src/controllers
2. In it, export the following elements:

export * from "./world-explorer-controller.intf"; 
export * from "./world-explorer-controller"; 

With that done, it'll be easier to later import our controller interface and implementation.