MMTEB Benchmarks considerations

[KennethEnevoldsen]

for the MMTEB submission, we do not have time to change this, but we do have time to change it afterward or jointly in response to reviews:

• 1. To make it easier for people to run multiple benchmarks it might be ideal to ensure that MTEB(multilingual) is a superset of MTEB(europe) and MTEB(indic)
• 2. MTEB(eng) is currently designed to match the original MTEB (MTEB(classic)), but we might as well use all the English tasks and then downsample, this would ensure much greater task diversity and include important novel tasks

Points arose in a discussion with @sivareddyg. There might be other worthwhile considerations