feat: add dark mode toggle

Signed-off-by: Richard Steinmetz <richard@steinmetz.cloud>

conf.py

@@ -8,7 +8,7 @@ dir_path = os.path.dirname(os.path.realpath(__file__))
 sys.path.insert(0, os.path.abspath(dir_path + '/_ext'))
 now = datetime.datetime.now()
 
-extensions = ['sphinx_rtd_theme']
+extensions = ['sphinx_rtd_theme', 'sphinx_rtd_dark_mode']
 
 # General information about the project.
 copyright = str(now.year) + ' Nextcloud GmbH'
@@ -70,3 +70,6 @@ html_context = {
 
 edit_on_github_project = 'nextcloud/documentation'
 edit_on_github_branch = 'master'
+
+# user starts in light mode
+default_dark_mode = False