update the readme, test=doc

demos/audio_content_search/README.md

@@ -5,7 +5,11 @@
 ACS, or Audio Content Search, refers to the problem of getting the key word time stamp from automatically transcribe spoken language (speech-to-text). 
 
 This demo is an implementation of obtaining the keyword timestamp in the text from a given audio file. It can be done by a single command or a few lines in python using `PaddleSpeech`. 
-
+Now, the search word in demo is:
+```
+我
+康
+```
 ## Usage
 ### 1. Installation
 see [installation](https://github.com/PaddlePaddle/PaddleSpeech/blob/develop/docs/source/install.md).

demos/audio_content_search/README_cn.md

@@ -6,6 +6,11 @@
 
 这个 demo 是一个从给定音频文件获取其文本中关键词时间戳的实现，它可以通过使用 `PaddleSpeech` 的单个命令或 python 中的几行代码来实现。
 
+当前示例中检索词是
+```
+我
+康
+```
 ## 使用方法
 ### 1. 安装
 请看[安装文档](https://github.com/PaddlePaddle/PaddleSpeech/blob/develop/docs/source/install_cn.md)。