Update onboarding steps

[06j07m]

List of changes:

• Updated setup steps in the documentation based on my onboarding
• Changed npm scripts for Windows to match the other scripts (i.e. start-windows uses the development environment and test-windows uses the test environment`)
• Added an npm script for Windows to seed databases since the other command didn't work for me
• Updated example .env file

Type of change

Documentation

How has this been tested?

I ran the commands on my (Windows) laptop