metadata / custom fields

[wingz1]

Can you update the README to explain how to specify the custom fields in the metadata.csv file and what new field names are allowed? (e.g. bring-your-own x and y umap positions or clusters or hot spots).
Thanks!

I just discovered this visualization work -- very cool -- would like to try it for video, too, with my own embeddings/mappings, etc.

[jrhorne]

Along with this, options to skip the existing image features and umap process if we're bringing our own embeddings.