Auto-add `timm` tag to timm-wrapper models. (#35794)
Works for fine-tuned or exported models:
```py
from transformers import AutoModelForImageClassification
checkpoint = "timm/vit_base_patch16_224.augreg2_in21k_ft_in1k"
model = AutoModelForImageClassification.from_pretrained(checkpoint)
model.push_to_hub("pcuenq/tw1")
```
The uploaded model will now show snippets for both the timm and the
transformers libraries.
