Refactor kubeadm config list-images

In preparation for creating a `kubeadm config images pull`
this commit refactors `kubeadm config list-images` into
`kubeadm config images list`.

Signed-off-by: Chuck Ha <ha.chuck@gmail.com>

docs/.generated_docs

@@ -58,7 +58,8 @@ docs/admin/kubeadm_alpha_phase_selfhosting_convert-from-staticpods.md
 docs/admin/kubeadm_alpha_phase_upload-config.md
 docs/admin/kubeadm_completion.md
 docs/admin/kubeadm_config.md
-docs/admin/kubeadm_config_list-images.md
+docs/admin/kubeadm_config_images.md
+docs/admin/kubeadm_config_images_list.md
 docs/admin/kubeadm_config_upload.md
 docs/admin/kubeadm_config_upload_from-file.md
 docs/admin/kubeadm_config_upload_from-flags.md
@@ -133,7 +134,8 @@ docs/man/man1/kubeadm-alpha-phase-upload-config.1
 docs/man/man1/kubeadm-alpha-phase.1
 docs/man/man1/kubeadm-alpha.1
 docs/man/man1/kubeadm-completion.1
-docs/man/man1/kubeadm-config-list-images.1
+docs/man/man1/kubeadm-config-images-list.1
+docs/man/man1/kubeadm-config-images.1
 docs/man/man1/kubeadm-config-upload-from-file.1
 docs/man/man1/kubeadm-config-upload-from-flags.1
 docs/man/man1/kubeadm-config-upload.1

docs/man/man1/kubeadm-config-images-list.1

@@ -0,0 +1,3 @@
+This file is autogenerated, but we've stopped checking such files into the
+repository to reduce the need for rebases. Please run hack/generate-docs.sh to
+populate this file.

docs/man/man1/kubeadm-config-images.1

@@ -0,0 +1,3 @@
+This file is autogenerated, but we've stopped checking such files into the
+repository to reduce the need for rebases. Please run hack/generate-docs.sh to
+populate this file.