Add automatic annotation to wtml with processing details

[astrodavid10]

I think it would be very useful to include an annotation in the resulting wtml file that details the specific toasty command run to process the data, the date of processing, and perhaps capture some info about the initial dataset as well, such as dimensions, bit depth, etc

[pkgw]

This is a great idea! We won't be able to automatically capture all details of processing for every dataset, but we could get a lot. Many astronomical data formats include a "history" field intended to capture this kind of information.