Add dark mode toggle to documentation

Author: falbrechtskirchinger

docs/mkdocs/mkdocs.yml

@@ -16,8 +16,21 @@ theme:
   name: material
   language: en
   palette:
-    primary: indigo
-    accent: indigo
+    - media: '(prefers-color-scheme: light)'
+      scheme: default
+      primary: indigo
+      accent: indigo
+      toggle:
+        icon: material/brightness-7 
+        name: Switch to dark mode
+    - media: '(prefers-color-scheme: dark)'
+      scheme: slate
+      primary: indigo
+      accent: indigo
+      toggle:
+        icon: material/brightness-4
+        name: Switch to light mode
+
   font:
     text: Roboto
     code: JetBrains Mono