Update homepage to design system and reorganize some content

[lukehollis]

Hey @ryaanahmed, I updated the homepage to the latest design system while hopefully making the project look somewhat independent while remaining as syndicated content to the main brand. Let me know if this is a good direction, and I'll continue updating the rest of the pages on the project. Some responsive fixes need to be added.

[ryaanahmed]

Yes - great direction! Sorry for taking ages to review -- here are some comments, but nothing blocking merge:

• Can we find some way to even more clearly give this project its own visual identity? The later projects had a more distinct independent visual identity, whereas this one didn't really. I like the use of the main design system, but let's try to find just one visual hook to say "this is its own thing".

• Let's make a prominent link to the code repo on GitHub on the project page, both to the original project and the gender analysis toolkit

great work!