Suggestion for disambiguation re import expectations and __init__.py

Issue Description

Having just gone through the tutorial, I found myself confused because once the project is packaged and installed, and then imported, the add_one() function seemed unavailable.

• "import example_package" was without error, but attempting to use example_package.add_one(3) gave AttributeError: module 'example_package' has no attribute 'add_one'

• "from example_package import add_one" gives ImportError: cannot import name 'add_one' from 'example_package'

• "from example_package import *" runs without error, but then attempting to use add_one gives NameError: name 'add_one' is not defined

The only way I have been able to run "add_one()" has been as
"from example_package.example import add_one".

While this is understandable as the function is defined in the top level example.py file, it definitely violated my expectations as almost every package I use would allow me to use "import example_package" and then "example_package.add_one()" or "from example_package import add_one" and then run "add_one()"

I am suggesting either an example of loading the package and using the function, or the addition of modifying the init.py to add "from .example import add_one"

Code of Conduct

• I am aware that participants in this repository must follow the PSF Code of Conduct.

Start by locating the tutorial's example_package/example.py and init.py files and read the surrounding packaging instructions. Decide whether the tutorial should document the nested import or expose add_one from init.py, then verify the documented import commands against the packaged example.