howto: use R&D cluster

@jpolchlo is deploying a working cluster for R&D purposes which would be a useful testing ground for the knowledge and the examples we build. We should have some simple steps for connecting to a cluster, inspecting resources, and changing its state (this can be broken down into sub-issues if that's sensible). Ideally, we will have a sense of at least the relevant `kubectl` commands and some screenshots with a few words talking about what we're looking at in `Lens` when connected to this cluster

Start by confirming access to the R&D Kubernetes cluster and reviewing the expected workflow for connecting to it. Document simple kubectl steps for connecting, inspecting resources, and changing cluster state, then add Lens screenshots with brief explanations. Done means a newcomer can follow the steps and understand the displayed resources.

Written by the indexing model from the issue text.