adding a debug mode in which you can render the FHR page with custom JSON

@laura r? To use this, simple open up config.json inside the js folder, set debug to true. Next open up json/payload.json and paste in the custom payload you want to test. Then simply run generate and load up the FHR page as you normally would.

To switch debugging off, simply set debug to false and it will render with data from the FHR data service.