Normally APP_NAME is used to set the name of the docker repo to which Jenkins X pipeline pushes to.
For nested repos, this is set to group/repo, which is valid for ECR repos as valid docker repo names can only contain abcdefghijklmnopqrstuvwxyz0123456789_-./.

However for dockerhub, this is not valid

This would also not work for repos with capitals in their name, as github repo names can have capital in their name, but dockerhub repo names cant have caps.