create and release a Docker image to run validations

[elray1]

this would likely live in a different repo, but am filing the issue here for now

[annakrystalli]

Here's a vignette on the workflow: https://65a1509bed4bd603ae77b0c2--hubverse-pkgdown-preview.netlify.app/articles/validate-submission

[nickreich]

I removed the assignees from this issue, as I don't think this is being actively worked on.