feat: working kubeflow-mlflow stack

[lukemarsden]

The working tutorial at https://github.com/boxkite-ml/boxkite/tree/master/examples/kubeflow-mlflow (https://boxkite.ml/en/latest/tutorials/kubeflow-mlflow/) is Apache 2 licensed and so we can just copy it into the kubeflow-mlflow stack https://github.com/combinator-ml/terraform-k8s-stack-kubeflow-mlflow, which is currently unfinished.

We should then document it and include a test drive link on the combinator website as well.