docs: Streamline and tidy backporting docs
docs: Streamline and tidy backporting docs

A couple of steps could be compressed into one, and this could make
better use of sphinx features to better format the steps.

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

tklauser/cilium,eloycoto/cilium,michi-covalent/cilium,tgraf/cilium,tklauser/cilium,scanf/cilium,michi-covalent/cilium,tgraf/cilium,cilium/cilium,michi-covalent/cilium,scanf/cilium,scanf/cilium,tklauser/cilium,tklauser/cilium,cilium/cilium,eloycoto/cilium,cilium-team/cilium,cilium/cilium,tklauser/cilium,cilium-team/cilium,eloycoto/cilium,cilium/cilium,eloycoto/cilium,cilium/cilium,eloycoto/cilium,scanf/cilium,michi-covalent/cilium,tgraf/cilium,tgraf/cilium,eloycoto/cilium,tgraf/cilium,scanf/cilium,eloycoto/cilium,michi-covalent/cilium,tgraf/cilium,scanf/cilium,scanf/cilium