Add the `Work` grouping column to the register table

One row per certificate, so the same DOI checked by several certificates repeats the same key - `create_register_files()`'s existing group-by machinery then puts them on one work page automatically.

Usage

add_work_key(register_table, register)

Arguments

register_table

The register table

register

The register from register.csv

Value

The register table with a `Work` column added