Fix docs command typo (#444)

docs/source/content/contributing.md

@@ -48,7 +48,7 @@ in the docstring, and this will then automatically generate the API docs when me
 They will also be automatically checked with [pytest](https://docs.pytest.org/) (via
 [doctest](https://docs.python.org/3/library/doctest.html)).
 
-If you want to view your documentation changes, run `pytest run docs-hot-reload`. This will give you
+If you want to view your documentation changes, run `poetry run docs-hot-reload`. This will give you
 hot-reloading docs (they change in real time as you edit docstrings).
 
 ### Docstring Style Guide