Update README: recommend float32 + sdpa for best native parity

README.md

@@ -59,7 +59,8 @@ checkpoint_dir = "allenai/MolmoWeb-8B"
 model = AutoModelForImageTextToText.from_pretrained(
     checkpoint_dir,
     trust_remote_code=True,
-    dtype="auto",
+    torch_dtype=torch.float32,
+    attn_implementation="sdpa",
     device_map="auto",
 )