Add option to copy image to clipboard

Closes #18 (closed).

Hi @z4ziggy, I have made a few modifications (source formatting), but I had to created a new MR because you did not enable the option to "Allow commits from members" and you created the MR from your master branch, which is protected.

Before merging, do you mind telling me your real name so I can update the commit author? If you prefer to keep your alias, no problem either 😃