Fix import path

[nudopnu]

Following the instruction of the docs for Packaging Entry Points does not work out of the box if you leave your __init__.py empty.

So either remind people to export their functions in their __init__.py or fix the import path specified in the pyproject.toml to hello.hello, resulting in:

    [project.scripts]
    hello = "hello.hello:cli"

[Rowlando13]

Good catch!