title: Git - Submodule to single file
body: <p>I have a project which use an external library hosted on GitHub. The external library is mine, but it needs to have an own repo because I use it in several projects. This library has the source code I need and a little demo in it. How can I do if I want to add as a submodule only the source code without the rest of the project (such as the demo files)? Is it possible? What is the best solution?</p>