i18n support #87

Similar to the solution in VuePress.

To enable multi-language support, you can use a special folder structure:

pages
├─ about.md
└─ zh-cn
   └─ about.md

Then, specify the locales option in saber-config.js:

module.exports = {
  siteConfig: {
    lang: 'en-US',
    title: 'My Website'
  },
  locales: {
    '/zh-cn': {
      siteConfig: {
        lang: 'zh-cn',
        title: '我的网站'
      }
    }
  }
}

You can override siteConfig and themeConfig in locales option.

this.$siteConfig will be computed based on $route.path:

// Under `/`:
this.$siteConfig
{
  lang: 'en-US',
  title: 'My Website'
}

// Under `/zh-cn`:
this.$siteConfig
{
  lang: 'zh-cn',
  title: '我的网站'
}