docs: add registry (quay.io/) for pre-loading images for kind
docs: add registry (quay.io/) for pre-loading images for kind

in doc, it recommends docker pull image, but the command is :
  docker pull cilium/cilium:|IMAGE_TAG|

this will download from docker.io
However, in operator, it loads images from quay.io
we should keep them the same, otherwise, we download for nothing.

Signed-off-by: adamzhoul <c8f2819851981a54fbb5d0c1e207d86f8d4adc6f@gmail.com>

michi-covalent/cilium,michi-covalent/cilium,cilium/cilium,cilium/cilium,michi-covalent/cilium,cilium/cilium,cilium/cilium,cilium/cilium,michi-covalent/cilium,michi-covalent/cilium