write a page about operator packaging

[clux]

as a peripheral part of the controller guide #5 under docs/controller/packaging.md

don't have experience with the operator lifecycle manager myself so not sure how much would be needed to talk about in the OLM section, but would like to learn this myself and i know there is interest to have it documented for rust. setting to help-wanted as a result.

rough idea of sections (feel free to change):

• how to package a controller (what yaml is needed)
• helm / kubectl
• RedHat's OLM (use case, benefits, what's needed)
• operatorhub?

this guide should probably be distinct from a development workflow, which is likely to use other tools like tilt/skaffold directly.