Refactor MKDocs configuration

The theme now follows the dark/light mode of the browser.

mkdocs.yml

@@ -13,18 +13,24 @@ theme:
   icon:
     logo: material/mushroom
   palette:
-    - scheme: default
+    - media: "(prefers-color-scheme: light)"
+      scheme: default
       primary: blue
       accent: light blue
       toggle:
         icon: material/brightness-7
         name: Switch to dark mode
-    - scheme: slate
+    - media: "(prefers-color-scheme: dark)"
+      scheme: slate
       primary: blue
       accent: light blue
       toggle:
         icon: material/brightness-4
         name: Switch to light mode
+    - media: "(prefers-color-scheme)" # This covers both light and dark system preferences
+      toggle:
+        icon: material/brightness-auto # Icon for automatic mode
+        name: Switch to light/dark mode (auto)
   features:
     - navigation.tabs
     - navigation.sections