Update get_tree_dicts Method Description in models/train.py

Method arguments and method arguments description are not similar.
[https://github.com/PatBall1/detectree2/blob/1823cd704a45ba4a0cc606bbfcfdcce5e4bba4d5/detectree2/models/train.py#L568](https://github.com/PatBall1/detectree2/blob/1823cd704a45ba4a0cc606bbfcfdcce5e4bba4d5/detectree2/models/train.py#L568)