Enhancement of Dark mode functionality

**Is your feature request related to a problem? Please describe.**
When a user switch dark mode on the website and refreshes the page it instantly gets disabled which does not looks appealing.
I want to enhance the functionality of dark mode.
**Describe the solution you'd like**
I will enhance this feature using JavaScript to implement local storage at the backend so the mode remains the same after refreshing the website.

**Describe alternatives you've considered**
I have considered changing the whole functionality of the dark mode toggler.

**Additional context**
I am willing to work on the issue kindly assign this to me under GSSOC23.