message: Changed PWD to pwd for bash examples
  Shell command PWD should be lowercase pwd for it work correct.  Obvious typo corrected.
diff: @@ -34,13 +34,13 @@ documentation](https://docs.docker.com/engine/reference/run/).
  # User permissions (-u) are required if you use (-v).
  # CPU-based images
  -$ docker run -u $(id -u):$(id -g) -v $(PWD):/my-devel -it tf
  +$ docker run -u $(id -u):$(id -g) -v $(pwd):/my-devel -it tf
  # GPU-based images (set up nvidia-docker2 first)
  -$ docker run --runtime=nvidia -u $(id -u):$(id -g) -v $(PWD):/my-devel -it tf
  +$ docker run --runtime=nvidia -u $(id -u):$(id -g) -v $(pwd):/my-devel -it tf
  # Images with Jupyter run on port 8888, and needs a volume for notebooks
  -$ docker run --user $(id -u):$(id -g) -p 8888:8888 -v $(PWD):/notebooks -it tf
  +$ docker run --user $(id -u):$(id -g) -p 8888:8888 -v $(pwd):/notebooks -it tf
  ```
  These images do not come with the TensorFlow source code -- but the development
  