Create setup script for setup of local dev environment

[GodVenn]

Describe the improvement you would like to see
A setup.sh script, which will create the necessary local .env files and such, so that a new developer simply has to clone repo, run this, and they should ideally be good to go.

How will this change existing functionality?
This will reduce onboarding time and save time on debugging set up issues when changes are made to the repo.

How will this improvement affect the current Threat Model?