Adds more instructions for using and running docker

examples/README.md

@@ -22,14 +22,14 @@ Under `model_examples` you'll find a how you could apply Hamilton to model your
 Check it out to get a sense for how Hamilton could make your ML pipelines reusable/general
 components...
 
-## Running examples through docker image
-Examples could also be executed through the provided docker image.
+## Running examples through a docker image
+Examples could also be executed through a docker image which you can build or pull yourself.
 Each example directory inside docker image contains a `hamilton-env` Python virtual environment.
 `hamilton-env` environment contains all the dependencies required to run the example.
 
-NOTE: If you already have the container image you can skip to container creation (step 3)
+NOTE: If you already have the container image you can skip to container initialization (step 3).
 
-1. Change directory to `examples`
+1. Change directory to `examples`.
 ```bash
 cd hamilton/examples
 ```
@@ -39,16 +39,31 @@ cd hamilton/examples
 docker build --tag hamilton-example .
 ```
 Docker build takes around `6m16.298s` depending on the system configuration and network.
-Alternatively, you can pull the container image from here: ...
+Alternatively, you can pull the container image from https://hub.docker.com/r/skrawcz/sf-hamilton.
+`docker pull skrawcz/sf-hamilton`.
 
-3. Creating a container
+3. Starting the container.
+If you built it yourself:
 ```bash
 docker run -it --rm --name hamilton-example hamilton-example
 ```
+If you pulled it from dockerhub:
+```bash
+docker run -it --rm --name hamilton-example skrawcz/sf-hamilton
+```
+This will start the container and put you into a bash prompt.
 
-4. Running the `hello_world` example inside the container
+4. Start running examples.
+E.g. running the `hello_world` example inside the container:
 ```bash
 cd hamilton/examples/hello_world
-source hamilton-env/bin/activate
+source hamilton-env/bin/activate  # this will activate the right python environment
 python my_script.py
+deactivate # this will deactivate the virtual environment so you can activate another
 ```
+To run another example:
+1. change directory to it.
+2. activate the environment (`source hamilton-env/bin/activate`).
+3. run the code, e.g. `python run.py`.
+4. deactivate the environment (`deactivate`).
+And then `exit` to quit out of the running docker container.