add gitignore and dark mode only

.gitignore

@@ -0,0 +1,3 @@
+.venv
+venv
+site

mkdocs.yml

@@ -3,26 +3,7 @@ theme:
   name: material
   language: de
   palette:
-
-  # Palette toggle for automatic mode
-  - media: "(prefers-color-scheme)"
-    toggle:
-      icon: material/brightness-auto
-      name: Switch to light mode
-
-  # Palette toggle for light mode
-  - media: "(prefers-color-scheme: light)"
-    scheme: default 
-    toggle:
-      icon: material/brightness-7
-      name: Switch to dark mode
-
-  # Palette toggle for dark mode
-  - media: "(prefers-color-scheme: dark)"
     scheme: slate
-    toggle:
-      icon: material/brightness-4
-      name: Switch to system preference
 markdown_extensions:
   - attr_list
   - md_in_html