Modify typesetting, test=doc

docs/source/tts/quick_start.md

+([简体中文](./quick_start_cn.md)|English)
 # Quick Start of Text-to-Speech
 The examples in PaddleSpeech are mainly classified by datasets, the TTS datasets we mainly used are:
 * CSMCS (Mandarin single speaker)

docs/source/tts/quick_start_cn.md

+(简体中文|[English](./quick_start.md))
 # 语音合成快速开始
 这些PaddleSpeech中的样例主要按数据集分类，我们主要使用的TTS数据集有：
 

examples/csmsc/tts3/README.md

+([简体中文](./README_cn.md)|English)
 # FastSpeech2 with CSMSC
 This example contains code used to train a [Fastspeech2](https://arxiv.org/abs/2006.04558) model with [Chinese Standard Mandarin Speech Copus](https://www.data-baker.com/open_source.html).
 

examples/csmsc/tts3/README_cn.md

+(简体中文|[English](./README.md))
 # 用 CSMSC 数据集训练 FastSpeech2 模型
 
 本用例包含用于训练 [Fastspeech2](https://arxiv.org/abs/2006.04558) 模型的代码，使用 [Chinese Standard Mandarin Speech Copus](https://www.data-baker.com/open_source.html) 数据集。