Add references between projects and todos

app/views/projects/show.html.erb

@@ -1,4 +1,9 @@
 <h1><%= @project.name %></h1>
+
+<% @project.todos.each do |todo| %>
+  <li><%= link_to todo.name, todo_path(todo) %></li>
+<% end %>
+
 <%= link_to "Edit", edit_project_path %>
 <%= button_to "Delete", project_path, method: :delete %>
 <%= link_to "Back", projects_path %>