gitbook 使用 ebook-convert 转换 pdf、mobi、epub 命令记录
```bash
ebook-convert
/var/folders/45/6z3zx6m51j31dc3xmr6tp9hr0000gn/T/tmp-13174sUZ20coWkit7/SUMMARY.html
/var/folders/45/6z3zx6m51j31dc3xmr6tp9hr0000gn/T/tmp-13174sUZ20coWkit7/index.pdf
--title=Gi