Missing sagemaker-rl-vw-container:adf image

I was trying to follow the walkthrough bandits_movielens_testbed walkthrough because I want to build and vowpal wabbit adf model and it seems that the `sagemaker-rl-vw-container:adf` image has been removed and theres no documentation on how to use it.

Start with the bandits_movielens_testbed walkthrough and trace where it references the sagemaker-rl-vw-container:adf image. Determine whether the image can be restored or whether the walkthrough needs updated usage instructions; done means the walkthrough has a working image path or documented replacement.

Written by the indexing model from the issue text.