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

Thanks Curtis Maloney for the original patch.

docs/intro/tutorial02.txt

@@ -34,8 +34,8 @@ settings:
 * :setting:`NAME` -- The name of your database. If you're using SQLite, the
   database will be a file on your computer; in that case, :setting:`NAME`
   should be the full absolute path, including filename, of that file. The
-  default value, ``os.path.join(BASE_DIR, 'db.sqlite3')``, will store the file
-  in your project directory.
+  default value, ``BASE_DIR / 'db.sqlite3'``, will store the file in your
+  project directory.
 
 If you are not using SQLite as your database, additional settings such as
 :setting:`USER`, :setting:`PASSWORD`, and :setting:`HOST` must be added.

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': [