How to find documentation about running a docker image

For example, there is an image named, khsibr/deepdream-nvidia

When I try to run it like so:

docker run -u 1000:1000 -it --rm khsibr/deepdream-nvidia

I get

Traceback (most recent call last):
File “deepdream.py”, line 38, in
img = np.float32(PIL.Image.open(’/data/%s’ % input_file))
File “/usr/lib/python2.7/dist-packages/PIL/Image.py”, line 2258, in open
fp = builtins.open(filename, “rb”)
IOError: [Errno 2] No such file or directory: ‘/data/input.png’

How do I do about figuring out what the author of the container expects me to pass as arguments?
The image above is based on google’s deepdream

In khsibr’s container , the root directory has a file , deepdream.py

but in the google repo the file is a python notebook, dream.ipynb

Clearly, khsibr has modified the file to run as a python program
When I go into the container with
docker run -u 1000:1000 -it --rm khsibr/deepdream-nvidia sh
I can see the file deepdream.py but I cannot run nano to read it.

How do I read the files in the image?
How do I ask the author?

The image neither has description, nor a link to a github repository.

The old version of Docker Hub allowed to add comments on repos, which is not possible anymore. So there is no way to get in touch with the author.

There is no way, except reverse engineering the entrypoint script and figuring out by your own how it might be intended.