Add Info: Set Huggingface Cache to avoid running into the HOME dir quota

Adding a hint for Huggingface users to change the HF cache directory for the dataset and model downloads. This avoids running unnecessary into the home dir quota.

export HF_HOME=/path/to/Workspace/.cache

More fine-grained environment variable definitions are here:https://huggingface.co/docs/huggingface_hub/package_reference/environment_variables