<https://gamedesignskills.com/game-design/how-to-write-a-game-design-document/#breadcrumb>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://schema.org/BreadcrumbList>
<https://gamedesignskills.com/game-design/how-to-write-a-game-design-document/>