Add result png

Signed-off-by: shiyu22 <shiyu.chen@zilliz.com>

README.md

@@ -27,19 +27,22 @@ This operator uses [PyTorch.yolov5](https://pytorch.org/hub/ultralytics_yolov5/)
 Writing the pipeline in the simplified way
 
 ```Python
-from towhee.dc2 import pipe, ops
+from towhee.dc2 import pipe, ops, DataCollection
 
 p = (
     pipe.input('url')
         .map('url', 'img', ops.image_decode.cv2_rgb())
         .flat_map('img', ('boxes', 'class', 'score'), ops.object_detection.yolo())
-        .output('class', 'score')
+        .flat_map(('img', 'boxes'), 'object', ops.towhee.image_crop())
+        .output('url', 'object', 'class', 'score')
     )
 
 res = p('test.png')
-res.get()
+DataCollection(res).show()
 ```
 
+<img src="./result.png" alt="result" height="340px"/>
+
 <br />