Citing GMT: Add single releases with their zenodo DOIs

[yvonnefroehlich]

Following this post on the GMT forum, https://forum.generic-mapping-tools.org/t/citation-information-add-doi-for-code-base-citation/6401 this PR tests / proposes to add the single GMT releases with their zenodo DOIs (https://doi.org/10.5281/zenodo.3407865) to the "Citing GMT" website page (https://www.generic-mapping-tools.org/cite/).

[yvonnefroehlich]

@ping @GenericMappingTools/gmt-maintainers and @g @GenericMappingTools/gmt-docs for feedback on this 🙂.

[seisman]

Does it make the page too long？Perhaps just show badges with doi links, similar to what we are doing in pygmt

[yvonnefroehlich]

Does it make the page too long？Perhaps just show badges with doi links, similar to what we are doing in pygmt

Oh yes, adding the Zenodo badges is a good idea and will look nice on the webpage.
Actually, I prefer to add the complete citation, even it makes the list a bit longer. So busy people can just copy the citation information, but more interested people can click on the links to get more information or download specific citation formats.

[seisman]

Please note that the source file is in ReST, not markdown.

[seisman]

Actually, I prefer to add the complete citation, even it makes the list a bit longer. So busy people can just copy the citation information, but more interested people can click on the links to get more information or download specific citation formats.

But people usually use a reference manager software, rather than copying the citation directly.