feat: Redesign the landing page

[EdwardPrado]

Describe your changes

Updated the landing page to match the Figma Redesign which is referenced in #70.

• Simple Icons package was added since Bootstrap icons didn't have all the social icons needed
• Updated constants to have consistent uppercase
• Redesign includes mobile support and dropdown navbar

Related issue number/link

Fixes #385

[VeckoTheGecko]

Looks good! Very excited for this. Just a note:

• In light mode, the contrast between the text and the hero image is a bit low making it difficult to read. In the design I think the opacity of the hero image started fading sooner than in this implementation. Could you patch that?

Other than that, I'll leave it up to you @dmlb to approve/merge this since I think you have more idea of what's going on in the code here :)