Flatten the Paper development hierarchy

[sowelipililimute]

This makes the content more immediately accessible and easier to browse through. Styling has also been adjusted as necessary to accomodate a flatter hierarchy of items; presenting content as a list with headers instead of a grid of cards.

ATM, the hierarchy of other stuff isn't flattened; I can do that if y'all like how it looks on the Paper dev pages.

before	after

[sowelipililimute]

In addition to the Doc Cards being weird on main admin/dev/contrib pages, I find it weird that the "Welcome to the paper docs" at the top of sidebars have a doc icon as well. Overall, I am a fan of the style though! thanks

fixed this

[olijeffers0n]

Could this be updated? If you are not able to, do not worry.