fleschReadingEaseScore method
Returns the Flesch reading ease score of the sourceText on a 100-point scale.
The higher the score, the easier it is to understand the document.
Authors should aim for score above 60.
Implementation
@override
double fleschReadingEaseScore() =>
206.835 - 1.015 * averageSentenceLength() - 84.6 * averageSyllableCount();