Explaining how to cite OCC datasets

[essepuntato]

We need to modify the download webpage so as to let reader know how to cite any of the dumps of the OpenCitations Corpus available on Figshare. A possible template (as suggested by Datacite):

Creator (PublicationYear): Title. Publisher. (resourceTypeGeneral). Identifier

For instance:

OpenCitations (2017). The OpenCitations Corpus dataset of all the bibliographic entries, made on 2017-07-25. Figshare. https://doi.org/10.6084/m9.figshare.5255323

[essepuntato]

It would be good to extend the download page adding the following text after the first paragraph:

Each dump is composed by several zip archives, each containing either data or provenance information relating to the entire corpus or to a particular sub-dataset within the OCC.

The correct bibliographic citation to use for each dataset, compliant with DataCite guidelines, is given on the Figshare page for that dataset, together with its Figshare DOI.

And then, maybe, to add an example as suggested above.