Update README.md

demos/text_to_speech/README.md

+
 # TTS(Text To Speech)
 
 ## Introduction
@@ -13,15 +14,35 @@ pip install paddlespeech
 
 ### 2. Prepare Input
 Input of this demo should be a text of the specific language that can be passed via argument.
-
-
 ### 3. Usage
-- Command Line(Recommended)
-  ```bash
-  paddlespeech tts --input 今天的天气不错啊
-  ```
-  Usage:
-  ```bash
+- Command Line (Recommended)
+	- Chinese
+	```bash
+	paddlespeech tts --input "你好，欢迎使用百度飞桨深度学习框架！"
+	 ```
+	The default acoustic model is `Fastspeech2`, and the default vocoder is `Parallel WaveGAN`.
+  - Chinese, use `SpeedySpeech` as acoustic model
+	```bash
+	  paddlespeech tts --am speedyspeech_csmsc --input "你好，欢迎使用百度飞桨深度学习框架！"
+	  ```
+   - Chinese, multi speaker
+	  ```bash
+	  paddlespeech tts --am fastspeech2_aishell3 --voc pwgan_aishell3 --input "你好，欢迎使用百度飞桨深度学习框架！" --spk_id 0
+	  ```
+  		You can change `spk_id` here.
+  - English
+	 ```bash
+	  	paddlespeech tts --am fastspeech2_ljspeech --voc pwgan_ljspeech --lang en --input "hello world"
+	  ```
+  - English, multi speaker
+	  ```bash
+	   paddlespeech tts --am fastspeech2_vctk --voc pwgan_vctk --input "hello, boys" --lang en --spk_id 0
+	   ```
+	   You can change `spk_id` here.
+	   
+ 
+- Usage:
+```bash
   paddlespeech tts --help
   ```
   Arguments:
@@ -79,7 +100,7 @@ Input of this demo should be a text of the specific language that can be passed
   ```
 
 
-### 4.Pretrained Models
+### 4. Pretrained Models
 
 Here is a list of pretrained models released by PaddleSpeech that can be used by command and python api: