📝 Add system icons note

Author: Schneegans

src/content/docs/icon-themes.mdx

@@ -29,11 +29,14 @@ Kando comes with a few icon themes pre-installed and you can easily add your own
 Kando comes with a few icon themes pre-installed. You can select them in the icon picker in the menu editor.
 Here's a list of the built-in icon themes:
 
-1. [Simple Icons](https://simpleicons.org) (Plain & Colored): A set of icons for popular brands.
-2. [Material Symbols Rounded](https://fonts.google.com/icons): An icon set for common actions and objects.
-3. Base64 / URL: This allows you to use any icon from the web or your local file system by providing a Base64-encoded string or a URL.
-4. Emojis: This allows you to use any emoji as an icon.
-5. Kando's own icons: Kando comes with a few icons which are used per default for new menu items.
+1. System Icons <Badge text="soon!" variant="tip" />: This special icon theme contains different icons depending on your operating system.
+   * On **Windows** and **macOS**, it contains the icons of the applications you have installed.
+   * On **Linux**, it contains the icons of the currently selected icon theme of your desktop environment. This means, the icons will change when you change your desktop environment's icon theme!
+2. [Simple Icons](https://simpleicons.org) (Plain & Colored): A set of icons for popular brands.
+3. [Material Symbols Rounded](https://fonts.google.com/icons): An icon set for common actions and objects.
+4. Base64 / URL: This allows you to use any icon from the web or your local file system by providing a Base64-encoded string or a URL.
+5. Emojis: This allows you to use any emoji as an icon.
+6. Kando's own icons: Kando comes with a few icons which are used per default for new menu items.
 
 The Simple Icons, the Material Symbols, and Kando's own icons are set up in such a way that they will change their color automatically based on the used menu theme.
 You can learn how to make your own icons behave like this further below!