add function for generating srt file (PaddlePaddle#3123)

* add function for generating srt file

在原来websocket_client.py的基础上，增加了由wav或mp3格式的音频文件生成对应srt格式字幕文件的功能

* add function for generating srt file

在原来websocket_client.py的基础上，增加了由wav或mp3格式的音频文件生成对应srt格式字幕文件的功能

* keep origin websocket_client.py

恢复原本的websocket_client.py文件

* add generating subtitle function into README

* add generate subtitle funciton into README

* add subtitle generation function

* add subtitle generation function

Author: twoDogy

README.md

@@ -178,6 +178,7 @@ Via the easy-to-use, efficient, flexible and scalable implementation, our vision
   - 🧩  *Cascaded models application*: as an extension of the typical traditional audio tasks, we combine the workflows of the aforementioned tasks with other fields like Natural language processing (NLP) and Computer Vision (CV).
 
 ### Recent Update
+- 🔥 2023.04.06: Add [subtitle file (.srt format) generation example](./demos/streaming_asr_server).
 - 🔥 2023.03.14: Add SVS(Singing Voice Synthesis) examples with Opencpop dataset, including [DiffSinger](./examples/opencpop/svs1)、[PWGAN](./examples/opencpop/voc1) and [HiFiGAN](./examples/opencpop/voc5), the effect is continuously optimized.
 - 👑 2023.03.09: Add [Wav2vec2ASR-zh](./examples/aishell/asr3).
 - 🎉 2023.03.07: Add [TTS ARM Linux C++ Demo](./demos/TTSArmLinux).

README_cn.md

@@ -183,6 +183,7 @@
   - 🧩 级联模型应用: 作为传统语音任务的扩展，我们结合了自然语言处理、计算机视觉等任务，实现更接近实际需求的产业级应用。
 
 ### 近期更新
+- 👑 2023.04.06: 新增 [srt格式字幕生成功能](./demos/streaming_asr_server)。
 - 🔥 2023.03.14: 新增基于 Opencpop 数据集的 SVS (歌唱合成) 示例，包含 [DiffSinger](./examples/opencpop/svs1)、[PWGAN](./examples/opencpop/voc1) 和 [HiFiGAN](./examples/opencpop/voc5)，效果持续优化中。
 - 👑 2023.03.09: 新增 [Wav2vec2ASR-zh](./examples/aishell/asr3)。
 - 🎉 2023.03.07: 新增 [TTS ARM Linux C++ 部署示例](./demos/TTSArmLinux)。