Add missing word to sentence in docs (#1552)

Add missing word to sentence in python 3 docs

changelog.d/1552.doc.rst

+Fixed a minor typo in the python 2/3 compatibility documentation.

docs/python3.txt

@@ -9,7 +9,7 @@ code.
 
 Setuptools provides a facility to invoke 2to3 on the code as a part of the
 build process, by setting the keyword parameter ``use_2to3`` to True, but
-the Setuptools strongly recommends instead developing a unified codebase
+the Setuptools project strongly recommends instead developing a unified codebase
 using `six <https://pypi.org/project/six/>`_,
 `future <https://pypi.org/project/future/>`_, or another compatibility
 library.