example-actions/sendemail.sh: add image attachment
example-actions/sendemail.sh: add image attachment

Optional attachment of detection image.
The image will be added as an attachment if the IMAGE_PATH
environment variable is set.

Signed-off-by: Erik Stromdahl <bceaca8caa2900989bb30a1257212196c3d2e7c8@gmail.com>

erstrom/opencv-home-cam,erstrom/opencv-home-cam