app/views/groups/index.html.erb
<h1>Listing groups</h1>
<table>
<tr>
</tr>
<% @groups.each do |group| %>
<tr>
<td><%= link_to 'Show', group_path(group.permalink) %></td>
<td><%= link_to 'Edit', edit_group_path(group.permalink) %></td>
<td><%= link_to 'Destroy', group.permalink, confirm: 'Are you sure?', method: :delete %></td>
</tr>
<% end %>
</table>
<br />
<%= link_to 'New group', new_group_path %>