Incomplete data file instructions in PyInstaller tutorial

[SirGnip]

Documentation request:

The PyInstaller bundling tutorial isn't handling paths correctly for user-provided data files: https://arcade.academy/tutorials/bundling_with_pyinstaller/index.html#handling-data-files

The instructions work when doing a one-directory bundle, but not when doing a one-file executable (--onefile). The most direct way to fix this is to add a little bit of code at the beginning of your app that changes the working directory if the app is running from a PyInstaller bundle. This way, games can use relative path names for resources regardless of whether the code is running normally, or running inside a bundle. Not the most sophisticated or flexible of approaches, but it probably most direct and understandable for beginners.

if getattr(sys, 'frozen', False) and hasattr(sys, '_MEIPASS'):
    print("Game is running from a PyInstaller bundle (aka 'frozen').")
    print("Therefore, changing current working directory to the root of bundle directory:", sys._MEIPASS)
    os.chdir(sys._MEIPASS)

The myriad of ways you can get at different directories related to running in a bundle are described here: https://pyinstaller.readthedocs.io/en/stable/runtime-information.html (which I'll link to in the PyInstaller tutorial).

I'll have a PR up for this, hopefully soon.

[SirGnip]

Done. Verbose, but more accurate.