feat: Add support for kubectl and jq inside docker image

[naphta]

I'm not really sure how to frame this (and I know I can just source from the current Dockerfile and build my own) but I was thinking it would be very useful for me at least and I expect others if there was a little bit more features added into the docker image.

If adding it into the base Dockerfile isn't okay; what about adding a slim / full variant of the images which have these extra features?

I'm happy to open a PR with the changes I just thought I'd run it through you guys before just doing it.