docs: dark mode

mkdocs.yml

@@ -9,9 +9,20 @@ theme:
   language: en
   name: material
   palette:
-    scheme: default
-    primary: deep orange
-    accent: indigo
+    # Palette toggle for light mode
+    - scheme: default
+      primary: deep orange
+      accent: indigo
+      toggle:
+        icon: material/brightness-7
+        name: Switch to dark mode
+    # Palette toggle for dark mode
+    - scheme: slate
+      primary: deep orange
+      accent: indigo
+      toggle:
+        icon: material/brightness-4
+        name: Switch to light mode
   features:
     # https://squidfunk.github.io/mkdocs-material/setup/setting-up-navigation/
     - navigation.instant