Design updates

[alexbainter]

Closes #60.

• Removes the faux document style to make the design cleaner and free up the total padding and margins around the document (especially on mobile)
  • Also moves the header/nav up to the top of the page
• Changes the datatype selection radios to be bigger and include the help text, removing the need for tooltips which are always awkward with touch inputs
  • Also removes the "[[DATATYPE]]: ..." label from the help text which was a bit redundant
• Styles the selects to match other elements
• Removes the striping on the article list table

I'm open to feedback & suggestions of course! (@Gogo-ug1?)

[alexbainter]

In draft while I add JS to scroll the selects into view when a data type is selected EDIT: Done