Add link to script for preparing imagenet val data

Author: achalddave

imagenet/README.md

@@ -7,6 +7,7 @@ This implements training of popular model architectures, such as ResNet, AlexNet
 - Install PyTorch ([pytorch.org](http://pytorch.org))
 - `pip install -r requirements.txt`
 - Download the ImageNet dataset and move validation images to labeled subfolders
+    - To do this, you can use the following script: https://raw.githubusercontent.com/soumith/imagenetloader.torch/master/valprep.sh
 
 ## Training