Function booklibrs::actions::genres::customize_book_genre

pub fn customize_book_genre(
    genres: &Genres, 
    book_system: &mut BookSystem, 
    reader_base: &ReaderBase, 
    caretaker: &mut Caretaker, 
    app: &App, 
    lang: Lang
)

Function that changes genres of all simple books and TheBook. You can choose as much genres as you need