feat: [GPU CI Runners] Document medium CIDRs + reorder list
feat: [GPU CI Runners] Document medium CIDRs + reorder list ref: https://gitlab.com/gitlab-com/gl-infra/reliability/-/issues/23695
feat: [GPU CI Runners] Document medium CIDRs + reorder list ref: https://gitlab.com/gitlab-com/gl-infra/reliability/-/issues/23695