Yes, the topic/knowledge taxonomy is an important part of it. There are ideas from ConceptNets to Faceted classification. For now, I have taken a pragmatic call to have maximum two parent topics for every topic node here. This allows me to show the hierarchy here: https://learnawesome.org/topics
This taxonomy design is being discussed here: https://github.com/learn-awesome/learn/issues/14
Feel free to suggest better approaches.