gh-113208: Mention namespace packages don't require __init__.py (#113209)

Co-authored-by: C.A.M. Gerlach <[email protected]>

Author: Unique-Usman

Doc/tutorial/modules.rst

@@ -437,7 +437,8 @@ When importing the package, Python searches through the directories on
 ``sys.path`` looking for the package subdirectory.
 
 The :file:`__init__.py` files are required to make Python treat directories
-containing the file as packages.  This prevents directories with a common name,
+containing the file as packages (unless using a :term:`namespace package`, a
+relatively advanced feature). This prevents directories with a common name,
 such as ``string``, from unintentionally hiding valid modules that occur later
 on the module search path. In the simplest case, :file:`__init__.py` can just be
 an empty file, but it can also execute initialization code for the package or