Faster workflow

[r002]

From yobi9's Discord comment on 3/10/21:

Faster workflow: The --snap features helps to quickly see result and speeds up calibration, but a UI would make that even faster, like NEStrisOCR or NEStrisChamps, but able to calibrate the fields for both players, rather than just one player at a time. Also with zoom on boundaries for pixel-perfect accuracy (like TechSmith's ImageCapture if you have ever seen that before)