pinyin
install
```shell script npm install pinyin
## how to use
```js
const pinyin = require('codes/pinyin');
let options = {
heteronym : true, // 启用多音字
style : pinyin.STYLE_NORMAL, // 普通拼音,不带声调
}
let result = pinyin('内容',{options});
/**
* style:
* '.STYLE_NORMAL' : 普通风格，不带声调 - ['pin', 'yin']
* '.STYLE_TONE' : 带声调,风格1 - ['pīn', 'yīn']
* '.STYLE_TONE2' : 带声调,风格2 - ['pin1', 'yin4']
* '.STYLE_TO3NE' : 带声调,风格3 - ['pi1n', 'yi4n']
* '.STYLE_INITIALS' : 只返回声母部分 - ['zh', 's', '']
* '.STYLE_FIRST_LETTER' : 只返回首字母 - ['y', 'z']
*
*/