feat: allow for custom registry

This patch adds a simple CLI which can mirror all the images needed
as well as allow for simple override for `atmosphere_image_repository`
for all images.
diff --git a/roles/containerd/defaults/main.yml b/roles/containerd/defaults/main.yml
index 2b742d1..60d4249 100644
--- a/roles/containerd/defaults/main.yml
+++ b/roles/containerd/defaults/main.yml
@@ -17,3 +17,5 @@
 containerd_pause_image: k8s.gcr.io/pause:3.5
 
                                                                    # ]]]
+
+containerd_insecure_registries: []