Redo jumbotron padding

Redo jumbotron padding

- In general, there are very few instances that would require a jumbotron without a parent or child container.
- Right now we account for that behavior though with some horizontal padding on the .jumbotron class.
- This removes that horizontal padding as it narrows our grid classes unnecessarily and accounts for a super small use case.
- It also improves consistency across breakpoints, in that padding isn't being added and removed.
- In doing so, I also removed the shorthand padding property and went with the specific ones (because yay specificity).