Generally this type of service is in a folder called config, or app-> config. The exceptions, which in my view would be files of a framework for example, fictionary in vendor.
This type of model is widely used by frameworks, such as Zend and Laravel (PHP Frameworks).
Zend folder structure:
-config
-autoload
-data
-cache
-module
-Application
-public
-css
-js
-image
-vendor
-zendframework
-bin
Since the config folder is responsible for the configuration files of the entire application. The folder dates to the files saved in the application. Module holds the files responsible for the mvc of each module of the application. Public is the folder responsible for the public files, much of these files used in the views. And vendor, where is the framework and various.