Support wysiwyg newline

Hi @chjj

## Changes

* add options wysiwyg line break

## add options wysiwyg line break

wysiwyg is option for simply new line break like wysiwyg editor and  github issue.


if wysiwyg is true : 

```
Hi all.
This is insanehong


I'm currently at naver corp as a front-end engineer.
bye see you.
```

#### Github Support this syntax on issue follow: 

Hi all.
This is insanehong


I'm currently at naver corp as a front-end engineer.
bye see you.