resumed work on the DSG files

Touched up and uploaded an Excel workbook for the Deep-Sky Gems observing list.

I had stalled on this work, activity I had started back in February. I had forgotten to wrap it all up.

Good to make some progress.

Once the Excel file was done, I exported a PDF version of the same. 

Uploaded it also to the DSG web page.

The Excel and PDF files reflect the current list from the RASC 2023 Observer's Handbook. In other words, it is the new stable list of targets after we locked down changes, additions, deletions, etc.

I let the Observing Committee team know. Asked if they might check my work.