[BETA] ToDo: text disappears upon saving and quitting

[TrapinchO]

Polyglot version: Windows BETA from 10th January 2022 (latest as of writing this) (might work on stable as well)

Steps to reproduce: 1) create new ToDo label, say test 2) save the file, say as test.pgd 3) close the file 4) reopen it 4a) the label is now invisible except the checkbox 5) create a new label, say test2 5a) both labels are now visible

notes:

• checkboxes remain check (or unchecked) as they were left

[DraqueT]

Huh! I hadn't considered that users might want this to be saved since the original zompist generator is a web app. Definitely a feature to include.