Commit / Edit / Diff models & their evaluation

[Muennighoff]

See https://huggingface.co/datasets/bigcode/evaluation/tree/main for results

Regarding the HumanEval change - the prior splitting was a bug imo as it does not work when there is | in the input

>>> x = """    return True <|endoftext|> hello def kk <|>|> """
>>> re.split("(%s)" % "|".join(["<|endoftext|>"]), x)
['    return True ', '<', '|', 'endoftext', '|', '>', ' hello def kk ', '<', '|', '>', '|', '>', ' ']

Closed in favor of: #120