Terminology and definitions in the core vocabularies

[aidig]

see https://github.com/SEMICeu/CPOV/issues/12

[barthelemyf]

The editors have:

• created (syntax) rules for writing definitions of the Core Vocabularies (Github link) – Feedback is welcome!
• reviewed the existing definitions w.r.t. to these rules and adapted them where needed – the supporting spreadsheet will be shared.

[EmidioStani]

Updated definitions have been published on: https://github.com/SEMICeu/Core-Person-Vocabulary/blob/master/releases/2.00/Changelog_definitions.md