Refactor example shortcode

data/structures/example.yml

@@ -0,0 +1,27 @@
+comment: >-
+  Display a code example and render a preview of the same input. The shortcode
+  accepts the languages supported by Hugo's highlight function.
+arguments:
+  lang:
+    type: string
+    optional: true
+    default: markdown
+    comment: Language used to display the code.
+  show_markup:
+    type: bool
+    optional: true
+    default: true
+    comment: Indicates if the markup should be output in the HTML.
+  show_preview:
+    type: bool
+    optional: true
+    default: true
+    comment: Indicates if the preview should be output in the HTML.
+  class:
+    type: string
+    optional: true
+    comment: Class attributes of the element's container.
+body:
+  type: string
+  optional: false
+  comment: The example input.

layouts/shortcodes/example.html

@@ -1,16 +1,27 @@
 <!-- 
+    Copyright © 2023 The Hinode Team / Mark Dumay. All rights reserved.
+    Use of this source code is governed by The MIT License (MIT) that can be found in the LICENSE file.
+    Visit gethinode.com/license for more details.
+
+    This source code adapts the original embedded shortcode as maintained by the The Bootstrap Authors. It introduces
+    the following modifications:
+     - Added validation of shortcode arguments
+     - Modified the layout
+    
+    The original source code is available on:
     Source: https://github.com/twbs/bootstrap/blob/main/site/layouts/shortcodes/example.html
-
-    Display a code example and render a preview of the same input. The shortcode accepts the languages supported by
-    Hugo's highlight function. The shortcode supports the following named arguments:
-
-    "id"            Optional identifier of the element's container.
-    "lang"          Language used to display the code, default value is "markdown".
-    "show_markup"   If the markup should be output in the HTML, defaults to "true".
-    "show_preview"  If the preview should be output in the HTML, defaults to "true".
-    "class"         Optional class attributes of the element's container.
+    Copyright (c) 2011-2023 The Bootstrap Authors. Licensed under The MIT License (MIT).
 -->
 
+{{ $error := false -}}
+
+<!-- Validate arguments -->
+{{ if partial "utilities/IsInvalidArgs.html" (dict "structure" "example" "args" .Params) }}
+    {{ errorf "Invalid arguments: %s" .Position -}}
+    {{ $error = true }}
+{{ end }}
+
+<!-- Initialize arguments -->
 {{- $id := .Get "id" | default "" -}}
 {{- $class := .Get "class" | default "" -}}
 {{- $lang := .Get "lang" | default "markdown" -}}
@@ -19,6 +30,7 @@
 {{- $content := .InnerDeindent -}}
 {{- if eq $lang "hugo" }}{{ $lang = "markdown" }}{{ end -}}
 
+<!-- Main code -->
 <div class="rounded border mb-3">
     {{- if eq $show_preview true -}}
         <div {{ with $id }}id="{{ . }}"{{ end }} class="rounded-top p-3 {{ with $class }} {{ . }}{{ end }}">