Remove remaining references to poetry shell

Author: johnthagen

docs/index.md

@@ -68,15 +68,16 @@ Then install the `fact` package and its dependencies:
 poetry sync
 ```
 
-Activate the virtual environment created automatically by Poetry:
+## Quick Start
+
+To run the included CLI:
 
 ```bash
-poetry shell
+poetry run fact 3
 ```
 
-## Quick Start
-
-To use `fact` within your project, import the `factorial` function and execute the API like:
+To use `fact` as a library within your project, import the `factorial` function and execute the
+API like:
 
 *[API]: Application Programming Interface
 

noxfile.py

@@ -26,7 +26,8 @@ def test(s: Session) -> None:
 
 
 # For some sessions, set venv_backend="none" to simply execute scripts within the existing Poetry
-# environment. This requires that nox is run within `poetry shell` or using `poetry run nox ...`.
+# environment. This requires that nox is run within the `poetry env activate` virtual environment
+# or using `poetry run nox ...`.
 @session(venv_backend="none")
 @parametrize(
     "command",