Support JSON file with an array of strings
Support loading a dataset from a JSON file with an array of strings.

See: https://huggingface.co/datasets/CausalLM/Refined-Anime-Text/discussions/1
https://huggingface.co/datasets/CausalLM/Refined-Anime-Text/discussions/1 has been fixed, but how can we check if there are other datasets with the same error, in datasets-server's database? I don't know how to get the list of erroneous cache entries, since we only copied `Error code:   JobManagerCrashedError`, but not the traceback in `details`... Do you remember the error message, or the underlying exception, we had?