When running a PyRat game, I get errors related to `freeze_support`

[BastienPasdeloup]

If you get this error:

RuntimeError:
        An attempt has been made to start a new process before the
        current process has finished its bootstrapping phase.

        This probably means that you are not using fork to start your
        child processes and you have forgotten to use the proper idiom
        in the main module:

            if __name__ == '__main__':
                freeze_support()
                ...

        The "freeze_support()" line can be omitted if the program
        is not going to be frozen to produce an executable.

        To fix this issue, refer to the "Safe importing of main module"
        section in https://docs.python.org/3/library/multiprocessing.html

It means that you are creating your games directly at the root of your games file, which can cause issues depending on the imports made. To solve this, if your code looks like this:

game = Game(...)
...

Change it to:

if __name__ == "__main__":
    game = Game(...)
    ...

And it should remove the error.