Add documentation for development setup on macOS

[Yukti-09]

Could I be assigned this?

[raj5036]

Can I work on this?

[orangecms]

Hi there, we will redo quite some bits around the docs; we already have some more up to date instructions at
https://docs.pslab.io/desktop/Readme.html. Please have a look there for now.

If you are running macOS and would like to help out, you are most welcome. :)
Please also share how you prefer to install the necessary dependencies since macOS is lacking a native system package manager for software distribution; Homebrew, MacPorts, extracting tarballs, .dmg images, installers, extra shell scripts (such as nvm for Node.js) are all possible; however, they are user-specific preferences and we should keep it their choice thusly. A little guidance for people with less experience leading to a somewhat maintainable/comprehensible procedure would be good, I think. Thank you!

[orangecms]

No specific assignment is necessary - just file PRs please so we can discuss them @raj5036 @Yukti-09 :)

[orangecms]

FYI: We now have builds for all platforms using GitHub Actions (see #652).

I edited the issue to be about the development setup.