usage stats on dataset pages

### Proposed change
number of citations and/or number of downloads for a dataset would be useful information on a dataset's homepage (sorry if I missed this). also it would be nice to have an easy way to export the citation as bibtex might be nice for computational users to encourage citation (many of us use latex).

### Alternative options
link to google scholar page for a dataset can show citations, e.g. like this one https://scholar.google.com/scholar?oi=bibs&hl=en&cites=1565589088577793300

### Who would use this feature?

I think dataset sharers could use this info to bolster their grant applications, to show they are collecting useful/unique/rigorous datasets

### (Optional): Suggest a solution