Update cdr-database articles to point to new project DOIs #193
Description
As we discussed in carbonplan/cdr-database#231, we now have DOIs for each version of the CDR-database. These DOIs should be added to the citation blocks of the three three research articles on the subject:
v1.0.0: https://zenodo.org/record/5715427
v1.1.0: https://zenodo.org/record/5715440
v1.2.0: https://zenodo.org/record/5715460