HF revamp

[jettjaniak]

• we never pass tokens as argument, it needs to be set in env variable HF_TOKEN
• training config needs out_repo_id - set to empty string if you don't want to upload to hf
  • if this is provided, every checkpoint and final model will be uploaded to HF
• training config has save_optimizer: bool = True
• changed folder structure for saved models to be easily loadable from HF

[SrGonao]

Ok

[jaidhyani]

lgtm