Add citation file, and maybe Zenodo json file

[bethac07]

A citation .cff woudl be good to have for citing this repository.

If we want to update the "type" in Zenodo to datasets rather than software, we probably need to put a .zenodo.json at the root of our repository - we can also add contributors affiliations/names/ORCIDs to this spec if we wish. This is a draft based on the metadata it provided the first upload, and its documentation for GH integraions. We can add papers as "related identifiers" as we like.

{
    "license": "other-open", 
    "title": "jump-cellpainting/datasets: JUMP-CP Datasets", 
    "upload_type": "dataset", 
    "access_right": "open", 
    "related_identifiers": [
        {
            "scheme": "doi", 
            "identifier": "10.5281/zenodo.7628768", 
            "relation": "isVersionOf"
        }
    ]
}

[bethac07]

(Alternately, we can decide we really don't care about what Zenodo metadata thinks we are, and use them as a DOI providing service and nothing else, but this seems relatively easy)

[shntnu]

We now have a citation https://zenodo.org/records/13179242!

Also see #126