Document ad-hoc API for election description classes
Document ad-hoc API for election description classes

Addresses https://github.com/openelections/core/issues/36

datamade/openelections-core,cathydeng/openelections-core,openelections/openelections-core,datamade/openelections-core,openelections/openelections-core,cathydeng/openelections-core