Add controller for Problems with index and show actions

app/views/problems/index.html.erb

@@ -0,0 +1,22 @@
+<h1>Listing Problems</h1>
+
+<%= render 'problem_pagination' %>
+<table class="table table-striped table-bordered">
+  <thead>
+  <tr>
+    <th>ID</th>
+    <th>Title</th>
+  </tr>
+  </thead>
+
+  <tbody>
+  <% @problems.each do |problem| %>
+      <tr>
+        <td><%= problem.id %></td>
+        <td><%= link_to problem.title, problem %></td>
+      </tr>
+  <% end %>
+  </tbody>
+</table>
+<%= render 'problem_pagination' %>
+<br>