Add example project

[bgeisb]

As an iOS developer,

I want to have an example project available in the "Tabify" Swift package repository on Github,

so that I can refer to it when implementing the package. I should be able to download and open the project to see how the Tabify package is used in an actual project.

I expect the example project to be well-commented and to explain how certain features of the Tabify package are used, so that I can easily understand how to integrate it into my own project.