How to run the operator locally

[appiepollo14]

Is your task related to a problem? Please describe.

As a contributor, it is unclear to me how to run the operator locally. In particular how to run the kuttl tests against a running operator. Examining the ci-build workflow doesn't give an explanation either.

Describe the solution you'd like

Update the developer-guide docs in the docs folder to explain in detail, which steps / make commands should be run to run the operator locally for fast development cycles.