[Documentation]: Extend README with prerequisites regarding Firebase and Java

[renestalder]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

Since the necessary Docker files were removed from the repository, the README requires developers to setup the development environment on the host machine. Therefore, it requires some prerequisites to get the setup running according to the current documentation.

When the current setup is done on a clean macOS install (assuming Node and NPM is installed), developers might run into following error:

➜  socialincome-public git:(main) npm run firebase:serve

> @socialincome/[email protected] firebase:serve
> firebase emulators:start --project social-income-staging --config firebase.json --import ./seed

⚠  emulators: You are not currently authenticated so some features may not work correctly. Please run firebase login to authenticate the CLI.
i  emulators: Shutting down emulators.

Error: Process `java -version` has exited with code 1. Please make sure Java is installed and on your system PATH.
-----Original stdout-----
-----Original stderr-----
The operation couldn’t be completed. Unable to locate a Java Runtime.
Please visit http://www.java.com for information on installing Java.

The README is currently missing any information about what needs to be preinstalled and what needs to be done to get the emulator running.

Steps To Reproduce

1. Clone the project on a clean machine
2. Install nodejs and npm
3. Try to setup project according to README

Expected Behavior

Developers should be able to follow the README step by step to get the project running.

Screenshots?

No response

Desktop Environment (please complete the following information)

- OS: macOS
- Browser: -
- Version: -

Smartphone Type (please complete the following information)

- Device: -
- OS: -
- Browser: -
- Version: -

Additional context

No response

Code of Conduct

• I've read the Code of Conduct and understand my responsibilities as a member of the Social Income community

[renestalder]

I can provide the installation steps for one environment.

Installation on macOS via Homebrew:

$ brew install openjdk
$ sudo ln -sfn $HOMEBREW_PREFIX/opt/openjdk/libexec/openjdk.jdk /Library/Java/JavaVirtualMachines/openjdk.jdk