Increase contrast of the scrollbar in dark mode

Author: doxygen

templates/html/darkmode_settings.css

@@ -31,7 +31,7 @@
 --blockquote-background-color: ##10;
 --blockquote-border-color: ##30;
 
---scrollbar-thumb-color: ##25;
+--scrollbar-thumb-color: ##35;
 --scrollbar-background-color: ##06;
 
 --icon-background-color: ##40;