Nimbus Screen Screenshot already does this and more

Nice that they will have a screenshot ability on Firefox. But the point of Firefox was a bare-bones browser where you can add functionality in the Add-Ons.
As for this plug-in, it needs:

  1. Entire page function and scrolling
  2. Copy to clipboard
  3. Settings for different formats, jpeg, gif, etc.
  4. Print option for making PDF’s
  5. Share buttons
  6. QR code scanning and recognition. (probably as an option)
  7. Options off of the toolbar icon.

Or you can just look at Nimbus Screenshot and ask them, since that plugin already does it all.
https://nimbus.everhelper.me/screenshot.php

At least these are my thoughts.