Code tabs in Markdown.

fixture

<div class="code-tabs">

```objc
NSLog(@"Some string");
```

```swift
var sortedStrings = sorted(stringArray) {
	$0.uppercaseString < $1.uppercaseString
}
```

</div>

```js
console.log("hej");
```

markdown-it-output.html

<div class="code-tabs">
    <pre>
        <code class="language-objc"><span class="hljs-built_in">NSLog</span>(<span class="hljs-string">@"Some string"</span>);</code>
    </pre>
    <pre>
        <code class="language-swift">var sortedStrings = sorted(stringArray) {
        <span class="hljs-variable">$0</span>.uppercaseString &lt; <span class="hljs-variable">$1</span>.uppercaseString
    }</code>
    </pre>
</div>

<pre>
    <code class="language-js"><span class="hljs-built_in">console</span>.log(<span class="hljs-string">"hej"</span>);</code>
</pre>

marked-output.html

<div class="code-tabs">

    <code>objc
    NSLog(@&quot;Some string&quot;);</code>
    
    <code>swift
    var sortedStrings = sorted(stringArray) {
        $0.uppercaseString &lt; $1.uppercaseString
    }</code>

</div>

<pre>
    <code class="lang-js">console.log(&quot;hej&quot;);</code>
</pre>