Feature request

Hello,

I have a use case where my team is sharing models and dataset in shared directory to avoid duplication.
I noticed that the cache documentation for datasets only mention the HF_HOME environment variable but never the HF_DATASETS_CACHE.

It should be nice to add HF_DATASETS_CACHE to datasets documentation if it's an intended feature.
If it's not, I think a depreciation warning would be appreciated.

Motivation

This variable is fully working and similar to what HF_HUB_CACHE does for models, so it's nice to know that this exists. This seems to be a quick change to implement.

Your contribution

I could contribute since this is only affecting a small portion of the documentation