Add Functionality for StarDist Parameters

[dl-mallory]

Hi! I was wondering if it could be added to the Docket to pass probability/NMS thresholds to StarDist, since that is the model ENACT works with. DIfferent probability thresholds for certain tissues need to be tested/evaluated empirically, and the default parameters don't work too well for my tissue.

I've just modified a downloaded version of the package and built from that, so it's not a rush.