format the python block in readme

README.md

@@ -28,7 +28,7 @@ source .venv/bin/activate
 uv pip install vismatch
 ```
 Usage
-```
+```python
 from vismatch import get_matcher
 from vismatch.viz import plot_matches
 
@@ -41,4 +41,5 @@ img1 = matcher.load_image("path/to/img1.jpg", resize=512)
 result = matcher(img0, img1)
 plot_matches(img0, img1, result, save_path="plot_matches.png")
 ```
+
 All model weights are hosted here and automatically downloaded by vismatch.