Added Education to seeds so that later example will work (#5610)

guides/contexts.md

@@ -405,7 +405,7 @@ $ mix ecto.migrate
 Now that we have a `Catalog.Product` schema and a join table to associate products and categories, we're nearly ready to start wiring up our new features. Before we dive in, we first need real categories to select in our web UI. Let's quickly seed some new categories in the application. Add the following code to your seeds file in `priv/repo/seeds.exs`:
 
 ```elixir
-for title <- ["Home Improvement", "Power Tools", "Gardening", "Books"] do
+for title <- ["Home Improvement", "Power Tools", "Gardening", "Books", "Education"] do
   {:ok, _} = Hello.Catalog.create_category(%{title: title})
 end
 ```