Add SmolLM

[jackzhxng]

🚀 The feature, motivation and pitch

Add SmolLM (135M, 360M, 1.7B). Should be directly using the Llama model architecture.

RFC (Optional)

#8228

cc @mergennachin @iseeyuan @lucylq @helunwencser @tarun292 @kimishpatel

[DavitGrigoryan132]

Hey @jackzhxng I would be happy to work on it

[Inklingdq]

Thanks @DavitGrigoryan132 for the interest! I've been working with @jackzhxng on this. Apologies for delay in updating the assignee