While this repo has the title "Dotfiles," it containes a much wider variety of text based configuration file examples beyond just dotfiles for systems that run Linux and also Windows.
Any sort of configuration file where someone might wish for an example version to help demonstrate the configuration options and the file format would be a good candidate for this repository (when I get around to adding such an example :)). The only time I will exclude such files is when the blanking or clearing of security sensative information (Such as passwords or usernames etc would make undersanding the sample configuration file very difficult. In this situation, if changing actual data to fake data (Password = "Passw0rd" instead of the real password) resolves the problem, I will do that instead.