Add hackathons section

[kevin-zou]

Description

Resolves #30. This PR adds the hackathon section to the landing page, complete with photos and some placeholder text.

I refactored the styling in the HackathonCard component since it had some weird behaviour on hover. It would show the image for the last hackathon (ie. cmd-f) regardless of which hackathon you were hovering. This was probably because the selector on line 19 (in the original code) came back with 3 options (as there are 3 CardContainers) and just gave back the last one by default (cmd-f).

Stop using ThemeContext

I realized that I don't always need to use ThemeContext to fetch theme properties, and therefore I do not need to declare styled components within the component function. I think this has been messing up the styling when statically exporting the site with Next.js, so let's see if this fixes it. Regardless this cleans up the code!

Other considerations

• refactored a bit of the Resources component after making some changes to the LinkBody typography component, @vincentchiang1 lmk if this is okay
• this doesn't have the star in the background, it was hard to implement and I think I went about it the wrong way - going to open an issue to come back to this and the other section backgrounds I've already done (Nit: section background trinkets not complete #84)

[github-actions]

Visit the preview URL for this PR (updated for commit ac43843):

https://nwplus-io--pr83-kevin-30-wvcrgdb4.web.app

_{(expires Mon, 06 Sep 2021 07:47:34 GMT)}

_{🔥 via Firebase Hosting GitHub Action 🌎}

[vincentchiang1]

aside from the nits with the constants, it looks superb!

[panjenny0]

🙏🙏🙏👏👏👏👏