Support a container registry other than Docker Hub

[gabe565]

Hello!

Yesterday, Docker sent an email stating they will be removing open source organizations within the next month, described by this unofficial blog post.

Since then, Docker has apologized for the miscommunication in this official blog post, but I still feel that Docker Hub may not be a safe provider of open source container images anymore.

I'd love to see a mirror of the pawelmalak/flame images in another container registry like GHCR or Quay.