chore: improve local setup

[anfern777]

Description

A script named local-setup.sh has been created to streamline the setup process for backend and frontend environments. The local setup instructions documentation has also been updated to be more organised, concise, and to reflect the addition of this new script.

Pre-review checks

Please ensure to do as many of the following checks as possible, before asking for committer review:

• [x] DEPENDENCIES are up-to-date. Dash license tool. Committers can open IP issues for restricted libs.
• [x] Copyright and license header are present on all affected files

[carslen]

@ClosedSourcerer please add an additional reviewer to review the introduced new code to the repo.