No more hard-coded values!

Instead of the logic being bound to PHPUnit Mocks by hard-coded values, the information that is required to fetch data from the StackExchange API has been completely moved to a separate file.

New FAQs can be added by adding an entry to the faq-lists.json with the required fields.

It is now also possible to overwrite configuration from the global scope.

All mentions of "PHPUnit Mocks FAQ" have been renamed to "faq.exchange"