Update CMS primary data sets

Addressing issues: https://github.com/cernopendata/opendata.cern.ch/issues/89 https://github.com/cernopendata/opendata.cern.ch/issues/333 https://github.com/cernopendata/opendata.cern.ch/issues/154 https://github.com/cernopendata/opendata.cern.ch/pull/91#discussion_r17281750
https://github.com/cernopendata/opendata.cern.ch/issues/223
This is supposed to be used in a proper citation which includes the CMS collaboration as creator + the CMS in the DOI (as discussed above) so there will be some context. Maybe @katilp has an opionion on adapting the title in a meaningful way.