Document custom Markdown heading renderer

docs/digging-deeper/advanced-markdown.md

@@ -161,6 +161,38 @@ anything within the path label will be rendered as HTML. This means you can add
 The filepaths are hidden on mobile devices using CSS to prevent them from overlapping with the code block.
 
 
+## Heading Permalinks
+
+Hyde automatically adds clickable permalink anchors to headings in documentation pages. When you hover over a heading, a `#` link appears that you can click to get a direct link to that section.
+
+### Usage & Configuration
+
+The feature is enabled by default for documentation pages. When enabled, Hyde will automatically add permalink anchors to headings between levels 2-4 (h2-h4). The permalinks are hidden by default and appear when hovering over the heading.
+
+
+You can disable the feature, or enable it for other page types, in the `config/markdown.php` file.
+
+```php
+// filepath: config/markdown.php
+'permalinks' => [
+    'enabled' => true,
+    'pages' => [
+        \Hyde\Pages\DocumentationPage::class,
+    ],
+],
+```
+
+### Advanced Customization
+
+Under the hood, Hyde uses a custom Blade-based heading renderer when converting Markdown to HTML. This allows for more flexibility and customization compared to standard Markdown parsers. You can also publish and customize the Blade component used to render the headings:
+
+```bash
+php hyde publish:components
+```
+
+This will copy the `markdown-heading.blade.php` component to your views directory where you can modify its markup and behavior.
+
+
 ## Dynamic Markdown Links
 
 HydePHP provides a powerful feature for automatically converting Markdown links to source files to the corresponding routes in the built site.