ShowcaseStrings constructor

const ShowcaseStrings({

String next = 'Next',
String done = 'Done',
String explanation = 'Explanation',
String outOfScope = 'This part is outside this demo.',
String featureOutOfScope(
1. String feature
) = _featureOutOfScope,
String finishTitle = 'Demo finished',
String finishMessage = 'You have seen the whole story. Do you want to start over?',
String keepLooking = 'Keep looking around',
String startOver = 'Start over',

})