DLC stores the following metadata:
https://github.com/DeepLabCut/DeepLabCut/blob/444da3da70b1f3bfaae39b0849e0aafcff1a9b7a/deeplabcut/pose_estimation_tensorflow/predict_videos.py#L750
(we are likely going to expand this in the near future). What other variables should be stored and could we put in NWB?