Clean up accessibility tree

[mattxwang]

Like many of my ideas for this website, this one comes from poking around Hack's (see uclaacm/hack.uclaacm.com#229) - our accessibility tree is rather disgusting.

In particular - the nav is poorly marked, many alt tags are not helpful, and the page is lacking a parseable structure.

Let's make this an "Epic" of sorts - we want to run manual audits and resolve them on:

• [ ] home page
• [ ] about page
• [ ] committees page (this one will be hard)
• [ ] events page
• [ ] sponsors page

Furthermore, for our new pages, let's build them in gracefully:

• [ ] internship page, #222
• [ ] events page / events archive page #179
• [ ] impact page
• [ ] jedi page
• [ ] dev team page
• [ ] "friends" page

Debating if this is a walkthrough I'll do with the dev team!

[mattxwang]

Some helpful resources:

https://developer.chrome.com/docs/devtools/accessibility/reference/

https://developers.google.com/web/fundamentals/accessibility/semantics-builtin/the-accessibility-tree

[mattxwang]

This should be easier now that #245 is merged!

[mattxwang]

This article (that I'm reading for work) is stellar: https://www.smashingmagazine.com/2021/03/complete-guide-accessible-front-end-components/

cc: @matthewcn56