[DOC] Refine Readme

Signed-off-by: LocoRichard <lichen.wang@zilliz.com>

README.md

@@ -24,7 +24,7 @@ This operator uses [PyTorch.yolov5](https://pytorch.org/hub/ultralytics_yolov5/)
 
 
 
-Writing the pipeline in the simplified way
+- Write the pipeline in the simplified way:
 
 ```Python
 import towhee
@@ -37,7 +37,7 @@ towhee.glob('./test.png') \
 
 <img src="./results1.png" alt="results1" height="40px"/>
 
-Writing the same pipeline with explicitly specified inputs and outputs
+- Write the same pipeline with explicitly specified inputs and outputs:
 
 ```Python
 import towhee
@@ -60,7 +60,7 @@ towhee.glob['path']('./test.png') \
 
 ## Factory Constructor
 
-Create the operator via the following factory method
+Create the operator via the following factory method:
 
 ***object_detection.yolov5()***
 
@@ -72,7 +72,7 @@ Create the operator via the following factory method
 
 ### Interface
 
-The operator takes an image as input. It first detects the objects appeared in the image, and gives the bounding box of each object.
+The operator takes an image as input. It first detects the objects appeared in the image, and generates a bounding box around each object.
 
 **Parameters:**
 
@@ -84,5 +84,5 @@ The operator takes an image as input. It first detects the objects appeared in t
 
 **Return**: List[List[(int, int, int, int)], ...], List[str], List[float]
 
-The return value is a tuple of (boxes, classes, scores). The *boxes* is a list of bounding boxes. Each bounding box is represented by the top-left and the bottom right points, i.e. (x1, y1, x2, y2). The *classes* is a list of prediction labels. The *scores* is a list of the confidence scores.
+The return value is a tuple of (boxes, classes, scores). The *boxes* is a list of bounding boxes. Each bounding box is represented by the top-left and the bottom right points, i.e. (x1, y1, x2, y2). The *classes* is a list of prediction labels. The *scores* is a list of confidence scores.