update readme

README.md

@@ -144,15 +144,23 @@ Compared to `jina-reranker-v2-base-multilingual`, `jina-reranker-m0` significant
     pip install transformers >= 4.47.3
     ```
 
+    If you run it on a GPU that support FlashAttention-2. By 2024.9.12, it supports Ampere, Ada, or Hopper GPUs (e.g., A100, RTX 3090, RTX 4090, H100),
+
+    ```bash
+    pip install flash-attn --no-build-isolation
+    ```
+
     And then use the following code snippet to load the model:
 
     ```python
     from transformers import AutoModel
 
+    # comment out the flash_attention_2 line if you don't have a compatible GPU
     model = AutoModel.from_pretrained(
         'jinaai/jina-reranker-m0',
         torch_dtype="auto",
         trust_remote_code=True,
+        attn_implementation="flash_attention_2"
     )
 
     model.to('cuda')  # or 'cpu' if no GPU is available