feat(tabs): add icon support for tabs (#926)

* feat(tabs): add icon support for tabs

- Introduced an `icon` property for tabs to display icons alongside tab labels.
- Updated the tabs shortcode and HTML partials to accommodate the new icon feature.
- Enhanced documentation for tabs to include examples of using icons in tab definitions.

* chore: rebuild css

* doc(tabs): add icon support in tab documentation for multiple languages

- Enhanced documentation for tabs to include examples of using the `icon` parameter in Persian, Japanese, and Simplified Chinese.
- Updated the tab shortcode examples to demonstrate how to display icons alongside tab labels.

* chore: regenerate compiled css

* fix(a11y): add aria-hidden to decorative tab icons

Add aria-hidden="true" to tab icon SVGs so screen readers skip
decorative icons and only announce the tab name. Update @example
docblock in tab.html to demonstrate the icon parameter.

* doc(tabs): improve icon section with better examples and icon page link

Rename "Tabs With Icons" heading to "Add Icons" for consistency with
other action-oriented section titles. Replace JSON/YAML/TOML icon
example with Photos/Music/Videos using photograph, music-note, and
film icons that naturally match their labels. Add link to the Icon
shortcode page so users can discover available icon names.

layouts/_shortcodes/tab.html

@@ -2,13 +2,16 @@
 Create a tab.
 
 @param {string} name The name of the tab.
+@param {string} icon The icon of the tab.
 @param {string} selected Whether the tab is selected.
 
-@example {{< tab name="Foo" selected=true >}}content{{< /tab >}}
+@example {{< tab name="Foo" icon="document-text" selected=true >}}content{{< /tab >}}
 */ -}}
 
 {{- $name := .Get "name" | default (printf "Tab %d" .Ordinal) -}}
 
+{{- $icon := .Get "icon" -}}
+
 {{- $selected := .Get "selected" -}}
 {{- if .Parent.Get "defaultIndex" -}}
   {{- $selected = eq .Ordinal (int (.Parent.Get "defaultIndex")) -}}
@@ -18,6 +21,7 @@ Create a tab.
 {{ .Parent.Store.Set "tabs" ($tabs | append (dict
     "id" .Ordinal
     "name" $name
+    "icon" $icon
     "content" .InnerDeindent
     "selected" $selected
   ))