Add Cohere dataset and configuration

[mihaic]

The Cohere HDF5 does not have a "distances" dataset. Since this is not used, we can make it optional.

[mihaic]

This dataset comes from OpenSearch:
https://github.com/opensearch-project/opensearch-benchmark-workloads/blob/main/vectorsearch/workload.json

[filipecosta90]

@mihaic can we add vector_count and description to the datasets. in this manner it will be better presented on the new way of showcasing the dataset:
❌ Errors:
❌ cohere-768-1M: Missing required field "vector_count"
❌ cohere-768-1M: Missing required field "description"
❌ cohere-768-10M: Missing required field "vector_count"
❌ cohere-768-10M: Missing required field "description"

[fcostaoliveira]

see: #30 (comment)

[mpozniak95]

I added both fields to cohere-1M and cohere-10M datasets

[filipecosta90]

thank you @mpozniak95 ! merging!