vdhanan: add ecr images to readme

JobBuild
998
07-28 00:25
pull-aws-ebs-csi-driver-e2e-multi-az 1420192171323035648 1420178517940768768
pull-aws-ebs-csi-driver-e2e-single-az 1420192171281092608 1420178517898825728
pull-aws-ebs-csi-driver-external-test 1420192171406921728 1420178518024654848
pull-aws-ebs-csi-driver-external-test-eks 1420192171448864768 1420178518066597888
pull-aws-ebs-csi-driver-migration-test 1420192171369172992 1420178517982711808
pull-aws-ebs-csi-driver-unit 1420192171226566656 1420178517856882688
pull-aws-ebs-csi-driver-verify 1420192171163652096 1420178517827522560