churn prediction example suggestions

[lebedov]

It appears that the location of the Generate Data Access Code menu entry has changed in the latest preview of the AML Workbench - the Data Access Code section of the docs should be updated accordingly. It should be made a bit more clear (e.g., for training) that the generated code is a skeleton that needs to be populated with code for data loading, encoding, etc.

The Execution – Local Docker Container should contain a note indicating that the Docker image in aml_config/docker.compute can only be run when Docker is set to run Linux containers (assuming that one isn't using a version with LCOW support).