[enh] Add Support for multiple adapters on Transformers-based models

[tomaarsen]

Supersedes #2993

Hello!

Details

Builds on top of #2993. I don't have permission to push directly into that PR as it's based on https://github.com/nuclia/sentence-transformers/tree/master to which I have no permission. So, I'm creating this PR to sidestep those issues.

cc @carlesonielfa

• Tom Aarsen

[tomaarsen]

@carlesonielfa
I've uploaded https://huggingface.co/sentence-transformers-testing/stsb-bert-tiny-lora (it includes a training script as well). The model card also shows that training with LoRA works!
I'm going to hustle to get this included in the next release, but that does mean that it won't have extensive documentation on launch. Ideally, I'd like to host a Training with PEFT documentation page on sbert.net, but that will have to come later.

P.s. if you're interested, you're free to help me get that set up! I'm not suuper familiar with PEFT.

cc @bloodbare for the PR

• Tom Aarsen

[carlesonielfa]

Great! Thank you so much for taking a look!

As for helping with the documentation, I’ll consider it! However, I’m not sure if I’ll have the time available.