Add option to clean all user changed settings like factory reset (feature request)

[grofaty]

It is super useful Pinta saving tiny customization like color, size of line etc.

But some times user can run into a problem, because he or she changes something and forgets to set back to original. I have run into some of those problems. Using Pinta/flatpak before reporting a bug I always manually delete Pinta's config file:
rm $HOME/.var/app/com.github.PintaProject.Pinta/config/Pinta/*

My feature request is to add some option for program to delete config files automatically. Like Help | "Clean user settings" and then confirmation dialog: "Clean all user made changes to Pinta settings?" "Clean" button and "Cancel" button.