Probably want to split nuskbygd_instrmap into two modules

[bwgref]

Right now it contains one module that makes the images showing which detector/pixel are the most dominant in which image pixel (which the user should probably never run themselves). We should split this off into its own module to reduce confusion.

The code then constructs the "newinstrmapA.fits" background files that are observation-specific. This is the only thing that should be in this module.