fix a small mistake in setup.rst

docs/tutorial/setup.rst

@@ -4,7 +4,7 @@ Step 2: Application Setup Code
 ==============================
 
 Now that we have the schema in place we can create the application module.
-Let's call it flaskr.py. We will place this file inside the flask folder.
+Let's call it flaskr.py. We will place this file inside the flaskr folder.
 We will begin by adding the imports we need and by adding the config
 section.  For small applications, it is possible to drop the configuration
 directly into the module, and this is what we will be doing here. However