start working on the state of the art, create group and add some refs

In mendeley, ohnosequences! research / metapasta-paper
do some research on the state of the art, add refs to mendeley
add references, fix DOIs for all of them

This is so time consuming but needs to be done. All of the refs there
have now a DOI (and pubmed ID). A lot of PDFs still missing though.
fix identifiers for refs, add PDFs
skim through reviews and surveys
Merge branch 'content/bibliography/state-of-the-art'