Add hydra section for WandB configs

It would be great to have additional wandb parameters one could use for wandb.init. Here the config https://github.com/knowledgetechnologyuhh/hipss/blob/518bf3e6a4d02e234cbe29506b9afda0a6ccb187/conf/misc.yaml#L18 and the initialization https://github.com/knowledgetechnologyuhh/hipss/blob/518bf3e6a4d02e234cbe29506b9afda0a6ccb187/train.py#L126 from the code of my latest paper.

Maybe as background, specifying the entity allows logging the metrics into different wandb teams. It is also quite helpful to add tags and a group label.