Add automatic segmentation example script

[anwai98]

Hi @titusgriebel,

Can you add an example script for automatic segmentation like the one in micro-sam to patho-sam? https://github.com/computational-cell-analytics/micro-sam/blob/master/examples/automatic_segmentation.py

Make sure that:

1. We use a histopathology dataset as example.
2. Keep the design super minimalistic and ready to fire in a few lines of code ;)

Once it's there, open a PR and put me to review!