Database initialization script to simplify onboarding 💨

[ramiAbdou]

Description

Currently, new contributors have to manually run commands to create the Postgres databases, and now to also create a Postgres role with password. We should instead allow them to run a script that automatically does that.

Acceptance Criteria

A contributor should just be able to run some sort of database initialization script that automatically runs these commands for them to create the role and databases.