Create ER diagram for data base schema

[erictleung]

Create vignette/article to describe this information and can talk about design thoughts here.

https://mermaid-js.github.io/mermaid/#/./entityRelationshipDiagram

Experiment:

erDiagram
    CAR ||--o{ NAMED-DRIVER : allows
    CAR {
        string registrationNumber
        string make
        string model
    }
    PERSON ||--o{ NAMED-DRIVER : is
    PERSON {
        string firstName
        string lastName
        int age
    }

From R: https://www.rdocumentation.org/packages/DiagrammeR/versions/1.0.9/topics/mermaid