Download only metadata

Hi

As we discussed I am writing my requirements here as an issue for future reference.

1. My main requirement is the ability to download only metadata. I'm not interested in the mrc files, only the particle positions, segmentations and other data uploaded.
2. I would like a function where I can do something like dataset.download("particles") or something like that. This function should look in all the possible locations for particles and return either the link to download or the data itself.
3. As we discussed, this could be implemented by doing an offline scan of Empiar to create a yaml or json file containing the known locations of metadata which could be updated by a github action and commited to a special branch on the github repo. That way the Pypi package would not have to be updated each time it changes.
4. If we could also expose a dictionary containing the contents of the xml file that would also be useful.

Best wishes
James