Fix Funnel configuration doc
# What does this PR do?

The part `standard deviation` should be `upper bound` in

https://github.com/huggingface/transformers/blob/cdc51ffd27f8f5a3151da161ae2b5dbb410d2803/src/transformers/models/funnel/configuration_funnel.py#L79-L80

as it is used for `nn.init.uniform_`:

https://github.com/huggingface/transformers/blob/cdc51ffd27f8f5a3151da161ae2b5dbb410d2803/src/transformers/models/funnel/modeling_funnel.py#L774-L778

@sgugger 
_The documentation is not available anymore as the PR was closed or merged._<|||||>Can you run `make style` on your brnach to fix the quality issue?<|||||>> Can you run `make style` on your brnach to fix the quality issue?

Sure - I forget doing so quite often (will try to be more careful!).<|||||>Thanks a lot!