docs: Fix broken link in 'How to add a model...' (#23216)

fix link

docs/source/en/add_new_model.mdx

@@ -678,7 +678,7 @@ model.save_pretrained("/path/to/converted/checkpoint/folder")
 **7. Implement the forward pass**
 
 Having managed to correctly load the pretrained weights into the 🤗 Transformers implementation, you should now make
-sure that the forward pass is correctly implemented. In [Get familiar with the original repository](#run-a-pretrained-checkpoint-using-the-original-repository), you have already created a script that runs a forward
+sure that the forward pass is correctly implemented. In [Get familiar with the original repository](#34-run-a-pretrained-checkpoint-using-the-original-repository), you have already created a script that runs a forward
 pass of the model using the original repository. Now you should write an analogous script using the 🤗 Transformers
 implementation instead of the original one. It should look as follows:
 

templates/adding_a_new_model/ADD_NEW_MODEL_PROPOSAL_TEMPLATE.md

@@ -848,7 +848,7 @@ model.save_pretrained("/path/to/converted/checkpoint/folder")
 Having managed to correctly load the pretrained weights into the 🤗
 Transformers implementation, you should now make sure that the forward
 pass is correctly implemented. In [Get familiar with the original
-repository](#run-a-pretrained-checkpoint-using-the-original-repository),
+repository](#34-run-a-pretrained-checkpoint-using-the-original-repository),
 you have already created a script that runs a forward pass of the model
 using the original repository. Now you should write an analogous script
 using the 🤗 Transformers implementation instead of the original one. It