Add a logo for OME-zarr

[dstansby]

I'm just writing a talk that includes a bit about OME-zarr, and I thought it would be great if there was a logo I could use to advertise it. Perhaps some sort of mashup of the OME and zarr logos?

[glyg]

Hi @dstansby there is an image.sc thread in the matter here:
https://forum.image.sc/t/is-there-an-ome-ngff-logo/

Guillaume

[joshmoore]

Thanks, @dstansby for the question & @glyg for cross-linking. I'll add here briefly that the primary blocker at the moment is the trademark issue, but we will get there.