Offer alternate sizes

[AllenEllis]

Right now the app only generates a single square image. From my Twitter DM:

If you could create a Printer Friendly template, something appropriately sized for an 8.5x11 piece of paper with optional b&w and with additional details about selected Yang policies

I've also heard other requests for business card sized as well (3.5 x 2").

Some thought needs to be put into the UI of how this would work. Should users just operate with the square preview, and once they click save, all possible sizes are generated at the bottom?

An alternate approach would be to have tabs or radio buttons beside the preview allowing users to change the preview in realtime. In that case, it would presumably only generate the size they selected.

This is a significant rearchitecture of how the backend works now. Everything from the code pipeline to the file structure for exports assumes there would only be one export per city/image combo.