news:
  en:
    name: News
    slug: news
    category: news
  es:
    name: Noticias
    slug: noticias
    category: noticias

book:
  en:
    name: Books
    slug: book
    category: book
  es:
    name: Libros
    slug: libro
    category: libro

Replace news category with book category in data
Replace news category with book category in data

Now the book category is known to the category generator.
