Implement decision_path in scikit.js #262

Is your feature request related to a problem? Please describe.
This is to return the path that shows how the decision tree makes decision on a label from the root to the leaf. My guess is that changes are needed here. Kindly provide a description of how it can be implemented, even if it is outside your project map.

Describe the solution you'd like

The Python implementation of scikit-learn has a def decision_path(self, X, check_input=True) in the source code

Provide suggestions on how it can be implemented in scikit.js.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered. This feature exist in scikit-learn.