text: Title: No demo assignment in topic-3
  Body: [jupyter_english/topic03_decision_trees_kNN](https://github.com/Yorko/mlcourse.ai/tree/main/jupyter_english/topic03_decision_trees_kNN) and [jupyter_french/topic03_decision_trees_kNN](https://github.com/Yorko/mlcourse.ai/tree/main/jupyter_french/topic03_decision_trees_kNN) has no .ipynb files for the demo assignment and solution to it. 
  Can you add them to the repo?