Add empty MD file to book

I'd love to see an "Add empty MD" option added to the:
Add Books > Add an empty file to selected book records

I'm also very curious if the contents of those "empty" files is somehow user-definable (a template maybe?). I noticed that the "empty" TXT file contains the books' current metadata title. Is this defined somewhere?

For me, it would be helpful if the "empty" MD could contain a full metadata header in the appropriate format.

Thank you everyone for all you contribute to both Calibre and its users.