Add dark mode and copy button

Author: dpvc

conf.py

@@ -33,7 +33,10 @@
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
-extensions = []
+extensions = [
+    'sphinx_copybutton',
+    'sphinx_rtd_dark_mode'
+]
 
 # Add any paths that contain templates here, relative to this directory.
 #templates_path = ['_templates']