Vocabulary for completeness of taxon indexing

[larsgw]

A major bottleneck for adding taxon indices to keys is that they are expected to be complete. Allowing partial resources (with proper indication of their completeness) removes this bottleneck.

levels:
  - ...
status:
  all_taxa: false # not all taxa included
  all_taxa_authorship: false # not all taxa with authorship included
  all_synonyms: false # not all synonyms included

The first/last/any key (decide) can also have all_resources: false to indicate not all resources are included.