Implement Dark/Light Mode Compatibility

[milinddethe15]

Enhance user experience and accessibility by implementing dark/light mode compatibility for the website.

Features:-

1. Dark Mode Integration

2. User Preference Persistence

3. Accessible Toggle

4. Theme Consistency

5. Testing and Feedback

[craigbox]

We had a light/dark mode before a redesign in 2020.

I am of the opinion that to have two themes requires you to have consideration for all assets (including images). This work has't happened yet, so we're likely to end up with figures that either render with a light background in dark mode, or are unreadable as they hard-code black text.

With that in mind we never brought dark mode back, and I would think you would need to do a lot of the "testing and feedback" in an evaluation phase 0 before starting this plan.