I have been following a tutorial on creating a C# project using TypeScript and Angular 2. However, when I attempt to add a TypeScript file to a folder, the window I see is different than what is shown in the tutorial. The window I get looks like this: https://i.sstatic.net/DVeHi.png
It does not contain the option to add a TypeScript file as shown in this image: https://i.sstatic.net/EVG8i.png
How can I make sure that the correct window is displayed when trying to add an item to a folder?