frontend inputs and outputs

[joshnorlin]

Some comments:

• After playing with a lot of different libraries, I decided that React LeafletJS with HTML Canvas would be best (for now) for displaying the user's prescription map
• Some of the output code will disappear once integrated with the backend, it's mostly there just to demonstrate current progress.
• The prescription output values are randomly generated
• Uploaded coordinate / yield files do not work, as I would argue that's a backend issue, and trying to temporarily demonstrate it would be too much work in my opinion