add OWNERS.md

[Noxsios]

Describe what should be investigated or refactored

Spawned from #2431 (review).

Adopt something like what porter does to clearly define who manages Zarf. This will become more critical after Zarf is donated to OpenSSF. It also serves to recognize emeritus status contributors and protect contribution history.

Links to any relevant code

/OWNERS.md

Additional context

Add any other context or screenshots about the technical debt here.