Fixed #29983 -- Replaced os.path() with pathlib.Path in project template and docs.

Thanks Curtis Maloney for the original patch.

docs/intro/tutorial07.txt

@@ -306,7 +306,7 @@ Open your settings file (:file:`mysite/settings.py`, remember) and add a
     TEMPLATES = [
         {
             'BACKEND': 'django.template.backends.django.DjangoTemplates',
-            'DIRS': [os.path.join(BASE_DIR, 'templates')],
+            'DIRS': [BASE_DIR / 'templates'],
             'APP_DIRS': True,
             'OPTIONS': {
                 'context_processors': [