Add light/dark theme to articles feed page

[NiallJoeMaher]

Context

So we can give a better user experience, we are working on a light/dark mode.

Expected Behavior

We use Tailwind so we should enable this by having a default light mode and dark mode with the dark: prefix.
You can see how this is done here: https://tailwindcss.com/docs/dark-mode

Current Behavior

By default, we only use a dark theme.
You can see the feed here: https://www.codu.co/articles

Additional info

The background for light mode should be: bg-neutral-100
The text should be: text-neutral-900
The cards should have a background of: bg-white

[pateldivyesh1323]

I would like to work on this.

[NiallJoeMaher]

All yours! Thanks @pateldivyesh1323