Automate pushing README's to ElasticContainerRegistry repo's for docker images

[pgroves]

Each 'tool' has it's own docker image and therefore it's own repository like:
https://gallery.ecr.aws/k1t6h9x8/phyloflow/vcf_transform

There isn't much automated information generated, so (if we get funded) this would be a nice place to push the README's in each tool directory and possibly the Dockerfile (as markdown) as well.

We could also do this for the dockstore entries if we continue with the Terra/dockstore ecosystem long term.