Feat: added toggle buttons and functiona darkmode to the landing page

[gbengaoluwadahunsi]

Summary This pull request introduces dark mode functionality and a toggle icon to our landing page.

Motivation We're striving to elevate user experience on our landing page by offering a dark mode option, making browsing more comfortable, especially during nighttime or in low-light environments.

Testing Extensive manual testing has been conducted across various browsers and devices to ensure seamless functionality and consistent visual presentation. Additionally, we've gathered user feedback to validate the effectiveness of the dark mode Questions Your feedback on these changes would be greatly appreciated. Please feel free to share any thoughts or concerns you may have.

[gbengaoluwadahunsi]

Hello@birm. I have separated my pull requests as you instructed, I unfortunately closed all my pull requests and only later got to know, that I am now reopening all of them, kindly review and merge the PR.