Use HF papers (#38184)

* Use hf papers

* Hugging Face papers

* doi to hf papers

* style

examples/modular-transformers/modeling_add_function.py

@@ -53,7 +53,7 @@ class TestAttention(nn.Module):
     Adapted from transformers.models.mistral.modeling_mistral.MistralAttention:
     The input dimension here is attention_hidden_size = 2 * hidden_size, and head_dim = attention_hidden_size // num_heads.
     The extra factor of 2 comes from the input being the concatenation of original_hidden_states with the output of the previous (mamba) layer
-    (see fig. 2 in https://arxiv.org/pdf/2405.16712).
+    (see fig. 2 in https://huggingface.co/papers/2405.16712).
     Additionally, replaced
     attn_weights = torch.matmul(query_states, key_states.transpose(2, 3)) / math.sqrt(self.head_dim) with
     attn_weights = torch.matmul(query_states, key_states.transpose(2, 3)) / math.sqrt(self.head_dim/2)