IsTranslated
报告给定页面是否有一个或多个翻译版本。
使用如下项目配置：
defaultContentLanguage = 'en'
[languages.en]
contentDir = 'content/en'
label = 'English'
locale = 'en-US'
weight = 1
[languages.de]
contentDir = 'content/de'
label = 'Deutsch'
locale = 'de-DE'
weight = 2内容如下：
content/
├── de/
│ ├── books/
│ │ └── book-1.md
│ └── _index.md
├── en/
│ ├── books/
│ │ ├── book-1.md
│ │ └── book-2.md
│ └── _index.md
└── _index.md渲染 content/en/books/book-1.md 时：
{{ .IsTranslated }} → true渲染 content/en/books/book-2.md 时：
{{ .IsTranslated }} → false