[getting started] generating routes manually was done as a learning

exercise, fix typos

guides/source/getting_started.textile

@@ -1194,17 +1194,18 @@ Also, if you go through the motions of creating, updating and deleting
 posts the app still works as before.
 
 TIP: In general, Rails encourages the use of resources objects in place
-of declaring routes manually. For more information about routing, see
+of declaring routes manually. It was only done in this guide as a learning
+exercise. For more information about routing, see
 "Rails Routing from the Outside In":routing.html.
 
 h3. Adding a Second Model
 
 It's time to add a second model to the application. The second model will handle comments on
-blog posts.
+posts.
 
 h4. Generating a Model
 
-We're going to se the same generator that we used before when creating
+We're going to see the same generator that we used before when creating
 the +Post+ model. This time we'll create a +Comment+ model to hold
 reference of post comments. Run this command in your terminal: