How to run Power BI Playground code on Github?

I downloaded and set up the PowerBIVisualsPlayground solution from Githup using vs 2015.  It runs ok, now I want to modify the Gauge visualisation (in the Visuals project, visuals/gauge.ts).  If I make changes in this file, then run solution, changes do not appear in the browser.  I am not familiar with this architecture so its all new - can anyone offer assistance on how this solution functions, or point me to a resource with assistance for this type of project?  Specifically, how do the projects in the solution get linked when you run the main project (PowerBIVisualsPlayground) ?  There is no bin folder and no website dll, no references set between projects.  Is everything linked via a config files ?  Help!