Add Mac requirements in the README

### Is your feature request related to a problem?

When running a node on mac OSx I was always getting an error `** (EXIT) {:listen_error, ArchethicWeb.Endpoint.HTTPS, eaddrinuse}` even though I wasn't personally running anything on port 4000 or 5000.

This error was due to Apple's AirPlay receiver being turned on by default and using port 5000.

### Describe the solution you'd like

Maybe add a simple line in the readme to prevent people from facing this issue.

See: https://developer.apple.com/forums/thread/682332?answerId=678289022#678289022

### Additional context

_No response_

Start by reading the README and locate the setup or Mac requirements section. Add a brief note about Apple's AirPlay Receiver using port 5000 and causing the reported listen error; the README should clearly warn Mac users about this setup issue.

Written by the indexing model from the issue text.