Quick doc and script fixes + missing folder

[rswezey]

• The specified TF version can't seem to be installed with Python 3.7, but everything works in 3.6
• Sorting model parameters explanation fix
• Variable fix in run_median.py
• elif fix in run_sort.py

Additionally, the dataset loader seems absent for the PyTorch code (I tried to use the one from the Flow-GAN repo but the code is different):

(neuralsort) root@85d56302ced7:/notebooks/neuralsort# cd pytorch
(neuralsort) root@85d56302ced7:/notebooks/neuralsort/pytorch# python run_dknn.py --k=9 --tau=64 --nloglr=3 --method=deterministic --dataset=cifar10 -startnew
setGPU: Setting GPU to: 0
Traceback (most recent call last):
  File "run_dknn.py", line 14, in <module>
    from dataset import DataSplit
ModuleNotFoundError: No module named 'dataset'