Add benchmarks and env file

[pollytur]

the submission file has a change because of this (it iterates across tiers, so the ood/ bonus naming should be consistent)

[yongrong-qiu]

Maybe I miss it, for the benchmark training notebook, maybe also include ensemble models?

[pollytur]

@yongrong-qiu But for training these are exactly same as the factorized ones and then the predictions are just averaged