Add an option and the first program to create screenshots

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.

0 files changed, 0 insertions, 0 deletions