k8s-conformance: Improve skipped tests format/links
k8s-conformance: Improve skipped tests format/links

The previous listing was harder to read because the individual tests
weren't listed in a markdown style. Furthermore, there are additional
issues to track each of the limitations which we can add to the listing
to help find/resolve them in future. Improve the comments in the test
script by adding bullet syntax and adding these links.

Signed-off-by: Joe Stringer <16a9a54ddf4259952e3c118c763138e83693d7fd@cilium.io>

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