This is the first step in creating additional programs for saving
screenshots for documentation purposes. These screenshots must be
saved in the documentation/images directory and checked into the
Git repository.
These programs allow developers to create new screenshots or change
existing ones. More screenshots may be created by programs in the
/test/ folder.
To-do: add more *new* screenshot programs, and if useful, move some
existing programs from the `/test/` folder to `/screenshots/`,
such as `test/resize-example*.cxx` and maybe more.
