This example shows how to call Article Editor for multiple textarea elements. Just specify the class or another group selector when you initializing it.
<!DOCTYPE html>
<html>
<head>
<title>Article Editor</title>
<meta charset="utf-8">
<!-- css -->
<link rel="stylesheet" href="/your-article-dist-path/article-editor.min.css" />
</head>
<body>
<!-- element 1 -->
<textarea id="entry-1" class="entry">
<p>Content</p>
</textarea>
<!-- element 2 -->
<textarea id="entry-2" class="entry">
<p>Content</p>
</textarea>
<!-- js -->
<script src="/your-article-dist-path/article-editor.min.js"></script>
<!-- call -->
<script>
ArticleEditor('.entry', {
css: '/your-article-dist-path/'
});
// get all running editors as an array
console.log(ArticleEditor.instances);
</script>
</body>
</html>