Update article page style for better readability

[anivanchen]

The page felt really packed which impacted both the readability (at the very least the ease of) of the article and the aesthetic look of the page.

Before

After

[leomet07]

Thanks for the PR Ivan (@anivanchen )!
Honestly I really dig the less-cramped vibe you added.
I'll probably still end up setting the article max-width to something a bit bigger, like 850px. But other than that, I'll just merge this :)

Thanks once again!

[anivanchen]

@leomet07 I was playing around with the max-width of the article and thought that the max-width being too large was contributing to the cramped feeling of the page so I lowered it to what looked right and found around 720px was a good balance.

You can probably also put ads on the side of the screen on desktop or short staff descriptions in the side margins to fill the space.