Add Detectron2 active learning framework (MaskAL)

[pieterblok]

@SkeletonOne thank you for setting up and maintaining this great overview of Detectron2 projects. I was wondering if you could add my Detectron2 active learning framework?

This active learning framework proved to significantly reduce the annotation effort for training Mask R-CNN in Detectron2. The code can be found here: https://github.com/pieterblok/maskal

There is also a paper publication: https://doi.org/10.1016/j.compag.2022.106917

Can you please add this project to your Github?

Thanks in advance!