Add CryoET Open Data to list of resources

[lubianat]

The CryoET Data Portal has many Zarr v2 datasets, and includes Zarr in their pipeline.

Overview of the data at this sandbox:

http://tiago.bio.br/ome2024-ngff-challenge/?csv=https://raw.githubusercontent.com/lubianat/ome2024-ngff-challenge/refs/heads/sandbox/samples/cryoet_manifest.csv

I have added a discussion at the CryoET GitHub forum about v3, as they seem quite active: chanzuckerberg/cryoet-data-portal#1966

PR #334