feature request: persistent storage of images already shown

[techducks]

Hey, thank you for this great project!

When using the image_order: random it always chooses randomly between all existing images, right?

Perhaps it is possible to save the images already displayed permanently (e.g. in a homeassistant entity). A new image is then only selected from the area of images not displayed. When all images have been displayed, the save point is reset.

This reduces the probability that an image will be displayed in quick succession.

Regards