Implement a dark mode for the website

## Problem

Currently, the website doesn't have a dark-mode implementation

## Description

Implementing a dark mode for a website can be a great way to improve the user experience and accessibility for users who prefer a darker colour scheme or have light sensitivity.
Here are a few things to keep in mind while implementing it:
- Ensure readability: In dark mode, the text should still be easily readable, with a high contrast ratio between text and background. The dark mode should not negatively impact the user's ability to read and understand the content on the website.
- Choose appropriate colours: Dark mode colour schemes should be carefully chosen to maintain a consistent look and feel with the light mode. The dark mode should not look like an afterthought, but rather a deliberate design choice that complements the overall design of the website. Dark colours should be chosen with care, avoiding colours that may be difficult for users with certain visual impairments, such as red-green colour blindness.
- Provide a toggle switch: Not all users may prefer dark mode, so it's important to provide a toggle switch to allow users to switch between light and dark mode as per their preference.

## Alternatives

## Additional context

## Implementation

- [x] I would be interested in implementing this feature.