Add historical entity schema v0.1.0

[jmwshye]

This schema is intended to represent historical entities
such as wars, people, battles and states.

It also uses the Murmurations relationships field to
represent semantic relationships between historical entities.

[olisb]

Hi @jmwshye thanks for your interest in Murmurations and creating this new schema.
In order to be publishable it will need some more thinking and additions... for example, most of the historical entities that fall under 'wars, people, battles and states' will need several other fields too like, start dates, end dates, geolocations and more... but I also wonder whether trying to lump all four historical entity types together is pragmatic... maybe it works ok, but people feel quite different e.g. to 'states' (although it's not clear exactly what type of states you mean?) and we already have a schema for people - although that is designed for living people so maybe historical people do warrant an additional schema....
Maybe if you can describe what you are aiming to map / classify and how we can help you develop this schema to make it more aligned with the objectives