Improved perspective script docs
Improved perspective script docs

USGS-Astrogeology/ISIS3_scripts,USGS-Astrogeology/ISIS3_scripts,thareUSGS/ISIS3_scripts,USGS-Astrogeology/ISIS3_scripts,thareUSGS/ISIS3_scripts,thareUSGS/ISIS3_scripts,USGS-Astrogeology/ISIS3_scripts,thareUSGS/ISIS3_scripts