It's a set of Visual Stuido item template for Revit Addin, hope you guys have fun with it.
Open Command Prompt and type cmd below:
$ git clone https://github.com/yiskang/RevitAddinTemplate.git "%USERPROFILE%\Documents\Visual Studio 2013\Templates\ItemTemplates\Visual C#\Revit"
In PowerShell:
$ git clone https://github.com/yiskang/RevitAddinTemplate.git "$Env:USERPROFILE\Documents\Visual Studio 2013\Templates\ItemTemplates\Visual C#\Revit"