remove dummy content store from heroku index page

We are retiring the dummy content store, so we can no longer show examples from this on the preview app. Instead, the real examples from the live site given further down on the page should suffice.

app/views/development/index.html.erb

@@ -42,36 +42,6 @@
           </tr>
         </table>
 
-        <h2>Examples</h2>
-
-        <p>
-          The content schemas contain <%= link_to 'handmade examples', 'https://github.com/alphagov/govuk-content-schemas/tree/master/examples' %>
-          for each schema rendered by this app. These are used in tests.
-        </p>
-
-        <p>
-          If this application is pointed at the <%= link_to 'dummy content store', 'https://github.com/alphagov/govuk-content-schemas/blob/master/docs/running-frontend-against-examples.md' %>
-          you can use the links below to view pages using the examples. For a
-          full list of examples, see <%= link_to 'govspeak-examples guide', 'https://govuk-content-store-examples.herokuapp.com' %>.
-        </p>
-        <table>
-          <% @schema_names.each do |schema_name| %>
-            <tr>
-              <td>
-                <%= schema_name %>
-              </td>
-              <td>
-                <%= link_to "Canonical example", "/examples/#{schema_name}/#{schema_name}" %>*
-              </td>
-              <td>
-                <%= link_to "Random example", "/examples/#{schema_name}/random" %>*
-              </td>
-            </tr>
-          <% end %>
-        </table>
-
-        * Will only work if this app is pointed at the <%= link_to 'dummy content store', 'https://github.com/alphagov/govuk-content-schemas/blob/master/docs/running-frontend-against-examples.md' %>.
-
         <h2>Examples from GOV.UK</h2>
 
         <p>These pages are good examples of the types of pages rendered by this application.</p>