Update README for new pipe

Signed-off-by: Jael Gu <mengjia.gu@zilliz.com>

README.md

@@ -18,48 +18,22 @@ As suggested, it is suitable to extract features at high level or warm up a larg
 
 Generate embeddings for the audio "test.wav".
 
-*Write the pipeline in simplified style*:
+*Write a pipeline with explicit inputs/outputs name specifications:*
 
 ```python
-import towhee
-
-(
-    towhee.glob('test.wav')
-          .audio_decode.ffmpeg()
-          .runas_op(func=lambda x:[y[0] for y in x])
-          .audio_embedding.vggish()
-          .show()
-)
-```
-    | [-0.4931737, -0.40068552, -0.032327592, ...] shape=(10, 128) |
-
-*Write a same pipeline with explicit inputs/outputs name specifications:*
+from towhee.dc2 import pipe, ops, DataCollection
 
-```python
-import towhee
-
-(
-    towhee.glob['path']('test.wav')
-          .audio_decode.ffmpeg['path', 'frames']()
-          .runas_op['frames', 'frames'](func=lambda x:[y[0] for y in x])
-          .audio_embedding.vggish['frames', 'vecs']()
-          .select['path', 'vecs']()
-          .show()
+p = (
+    pipe.input('path')
+        .map('path', 'frame', ops.audio_decode.ffmpeg())
+        .map('frame', 'vecs', ops.audio_embedding.vggish())
+        .output('path', 'vecs')
 )
+
+DataCollection(p('./test.wav')).show()
 ```
-    [array([[-0.4931737 , -0.40068552, -0.03232759, ..., -0.33428153,
-          0.1333081 , -0.25221825],
-        [-0.49023268, -0.40161428, -0.03255743, ..., -0.33395663,
-          0.13261834, -0.25324696],
-        [-0.4992406 , -0.39848825, -0.03186834, ..., -0.33684137,
-          0.13326398, -0.25385314],
-        ...,
-        [-0.49047503, -0.40119144, -0.03144619, ..., -0.33282205,
-          0.13334712, -0.2520305 ],
-        [-0.48861542, -0.40097567, -0.03173053, ..., -0.33255234,
-          0.13278192, -0.25157905],
-        [-0.4886143 , -0.40098593, -0.03175077, ..., -0.3325425 ,
-          0.13271847, -0.25159872]], dtype=float32)]
+
+<img src="./result.png" width="800px"/>
 
 <br />