User/itlinde/640 about page improvements

[itlinde]

Description

• Resolves Improve 'About Page' Layout with Paragraphs and Images #640
• Uses GSAP to make a sticky scroll animation (one side of the page scrolls normally and the other side animates based on the scroll position)
• Separates downloads into their own page
• Animates the about and download pages on load
• Adds a last updated line to each dataset download
• Adds a new API route to get the last updated timestamps of each dataset so the frontend doesn't need to go through every single dataset

Verification

• Animations work scrolling up/down the page
• Animations work when scrolling at different speeds
• Download links still work for all datasets
• Last Updated lines handle empty datasets
• New download page links work

Resources

• gsap docs (https://gsap.com/docs/v3/)