Finish second theme page - Data Deposition

[karthik]

We need a shorter version of how to deposit data using rfigshare, then grab a DOI back into say a Rmd file.

Soon we can add more to this like using EML, using other services like dvn and zenodo.

[karthik]

Other things to add here:

git2r DVN gistr

and actually make the theme reproducibility rather than just 'data deposition'.