Write benchmark code for ImageNet

# Write benchmark code for ImageNet

Similar to the benchmarks we have for [Cifar10 and Imagenette](https://docs.lightly.ai/getting_started/benchmarks.html), we should write the benchmark code for `ImageNet` with the parameters from the respective papers. This will allow us to 
- provide a model zoo of different pre-trained ResNets on `ImageNet`
- validate our implementations on `ImageNet`