Create darkmode switch

[Thenlie]

Darkmode 🌞 🌚

Create a darkmode switch and darkmode color palette for the site. The darkmode needs to include a new highligh.js theme.

• Create switch
• Implement initial body styling, connect to switch
• Add hilight.js theme
• Finalize styling, double check mobile

[Thenlie]

❗ Branch created. Checkout with the command below ⬇️

git fetch origin
git checkout 30-feature/darkmode

NOTE: Be sure to run git merge main after the command above.