Update README

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

README.md

@@ -49,7 +49,7 @@ $ pip3 install towhee
 >>> from towhee import pipeline
 >>> from PIL import Image
 
->>> img = Image.open('path/to/your/image')
+>>> img = Image.open('path/to/your/image') # for example, './test_data/test.jpg'
 >>> embedding_pipeline = pipeline('towhee/image-embedding-resnet50')
 >>> embedding = embedding_pipeline(img)
 ```
@@ -62,7 +62,7 @@ First of all, you need to learn the pipeline and operator in Towhee architecture
 
 - **Operator**: An `Operator` is a single node within a pipeline. It contains files (e.g. code, configs, models, etc...) and works for reusable operations (e.g., preprocessing an image, inference with a pretrained model).
 
-This pipeline includes four functions: `_start_op`, `towhee/transform-image`, `towhee/resnet50-image-embedding` and ` _end_op`. It is necessary to ensure that the input and output of the four Operators correspond to each other, and the input and output data types can be defined by DataFrame.
+This pipeline includes four functions: `_start_op`, `towhee/transform-image`, `towhee/resnet50-image-embedding` and `_end_op`. It is necessary to ensure that the input and output of the four Operators correspond to each other, and the input and output data types can be defined by DataFrame.
 
 ![img](./pic/pipeline.png)