Fix ffn link (#892)

* Fix ffn link

* Apply suggestion from @rasbt

* Apply suggestion from @rasbt

Author: rasbt

ch04/07_moe/README.md

@@ -98,7 +98,7 @@ uv run plot_memory_estimates_moe.py \
  
 ## MoE Code Examples
 
-The [gpt_with_kv_moe.py](gpt_with_kv_moe.py) and [gpt_with_kv_moe.py](gpt_with_kv_moe.py) scripts in this folder provide hands-on examples for comparing the regular FFN and MoE memory usage in the context of a GPT model implementation. Note that both scripts use [SwiGLU](https://arxiv.org/abs/2002.05202) feed-forward modules as shown in the first figure of this page (GPT-2 traditionally uses GELU).
+The [gpt_with_kv_ffn.py](gpt_with_kv_ffn.py) and [gpt_with_kv_moe.py](gpt_with_kv_moe.py) scripts in this folder provide hands-on examples for comparing the regular FFN and MoE memory usage in the context of a GPT model implementation. Note that both scripts use [SwiGLU](https://arxiv.org/abs/2002.05202) feed-forward modules as shown in the first figure of this page (GPT-2 traditionally uses GELU).
 
 **Note: The model is not trained and thus generates nonsensical text. You can find a trained MoE in the bonus materials at [../../ch05/11_qwen3/standalone-qwen3-moe-plus-kvcache.ipynb](../../ch05/11_qwen3/standalone-qwen3-moe-plus-kvcache.ipynb).**