Add documentation dark theme

Signed-off-by: Emmy D'Anello <emmy.danello@animath.fr>

docs/conf.py

@@ -29,6 +29,7 @@ author = "Animath"
 # ones.
 extensions = [
     "sphinx_rtd_theme",
+    "sphinx_rtd_dark_mode",
 ]
 
 # Add any paths that contain templates here, relative to this directory.
@@ -58,3 +59,5 @@ html_theme = 'sphinx_rtd_theme'
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
 html_static_path = ['_static']
+
+default_dark_mode = True

docs/requirements.txt

@@ -1,2 +1,3 @@
 sphinx>=3.3
-sphinx-rtd-theme>=0.5
+sphinx-rtd-theme>=2.0
+sphinx_rtd_dark_mode>=1.3.0