Decide if kind should be renamed to resource

[hbagdi]

What would you like to be added:

Rename kind to resource for object references as per API conventions: https://github.com/kubernetes/enhancements/blob/master/keps/sig-api-machinery/2336-OwnerReference-resource-field/README.md

Why this is needed:

Upstream API conventions recommend "resource" over "kind"

Concerns

Some concerns were raise in the community meeting (not exhaustive):

• Do client-go or controller-runtime supported?
• This is a change of a large magnitude and nobody on the call really seems to be aware of these details.

[hbagdi]

xref #689

[robscott]

As referenced in #689, I think kubernetes/community#5748 (comment) is probably the best summary of the rationale for this change, will continue to follow up on this one.

[youngnick]

I think the biggest thing we, as a community will need to do, is do more education of what users will actually need to put in there. Usually it's lower-case, pluralised, instead of Initialcase, so we should probably put in some examples in the docs for the field.

[robscott]

Followed up on mailing lists: https://groups.google.com/g/kubernetes-sig-architecture/c/WhHTjTDzcQg

[robscott]

Working on update to API conventions: kubernetes/community#5973

[youngnick]

Feels like we agreed that, as long as the API conventions update goes in, we will not be changing Kind to Resource. Other maintainers thoughts?

[robscott]

API conventions have been updated (kubernetes/community#5973), I think the only remaining step is to document why we chose Kind over Resource and more importantly, what that means for implementations of this API.

[robscott]

/assign