Create MarginalIndependence page
This creates a stub page for our paper on Marginal Independence Models.
I realize that mathrepo is not for "parking" empty pages with promises of being filled with data, but we would like to have a stable URL for our preprint (to be published still this month) as soon as possible. Almost all data and code are ready and we are prepared to upload them in the coming days and weeks, after another careful check and cleanup.
I hope this is acceptable.