simplify citation of the CKAN software itself

Hello!

Reading through some discussions about DOIs in CKAN, I remained wondering how CKAN itself should be cited? For example when an academic projects develops an extension and wishes to publish in a journal. Is there a guideline how to do that?

If not, there would be the simple option of a [BibTeX-based `CITATION` file](http://blog.rtwilson.com/encouraging-citation-of-software-introducing-citation-files/) or a more advanced [`codemeta.json`](https://codemeta.github.io/) ([example](https://github.com/codemeta/codemeta/blob/master/examples/example-code-jsonld.json)).

In a `CITATION` file, you could choose to an have CKAN cited via an `@article{...`, `@manual{...`, or `@book{...` (like [ggplot2](https://cran.r-project.org/web/packages/ggplot2/citation.html)). Or of cource `@software{...` :-)

What do you think about this idea? I'd volunteer to cobble together the metadata for these files and start a PR.

Cheers, and happy holidays :-)

Review the proposed BibTeX-based CITATION file and codemeta.json approaches linked in the issue. First establish which citation format and metadata CKAN should support; done would be agreed citation guidance and a defined metadata artifact.

Written by the indexing model from the issue text.