Document blueprint/deployment workflows, with diagrams

[bgrant0607]

Existing workflows are described at the package level: https://kpt.dev/book/02-concepts/02-workflows

Now that we're establishing the blueprint / deployment distinction and are introducing package orchestration, we should describe the higher-level workflows and also update the terminology.

This kustomize talk has a bunch of diagrams that we could use for inspiration: https://www.youtube.com/watch?v=EZ7kxa2GKYQ

I have the source deck, though it's not fully public.