How do I build my own extension?
To continue with this section, you will need to be registered for VSO Extensions and have a publisher ID with which you have permissions to publish set up (https://www.visualstudio.com/integrate/extensions/publish/overview).
I usually use Visual Studio or Visual Studio Code to develop VSO Extensions. However, you can use any other editor if you want to. Visual Studio is the preferred way of creating these extensions for me at least:
I mostly use TypeScript, which works nicely in Visual Studio, instead of raw JavaScript
Visual Studio also easily configures SSL in IIS Express for you, which is a requirement for VSO Extensions
A new empty web application is usually a good starting point for one of these projects. The other option is to use the Visual Studio template by Josh Garverick (https://visualstudiogallery.msdn.microsoft.com/a00f6cfc-4dbb-4b9a-a1b8-4d24bf46770b). It does what is explained as follows. When you have created a new empty web application project...
