add blank ammo types page

lib/cannery_web/live/ammo_type_live/index.html.heex

@@ -3,6 +3,15 @@
     Listing Ammo Types
   </h1>
 
+  <%= if @ammo_types |> Enum.empty?() do %>
+    <h2 class="title text-xl text-primary-500">
+      No Ammo Types 😔
+    </h2>
+
+    <%= live_patch "Add your first type!",
+      to: Routes.ammo_type_index_path(@socket, :new),
+      class: "btn btn-primary" %>
+  <% else %>
     <%= live_patch "New Ammo type",
       to: Routes.ammo_type_index_path(@socket, :new),
       class: "btn btn-primary" %>
@@ -39,6 +48,7 @@
         </tbody>
       </table>
     </div>
+  <% end %>
 </div>
 
 <%= if @live_action in [:new, :edit] do %>