Update _details.html.erb

app/views/customers/_details.html.erb

@@ -25,6 +25,11 @@
       <td><%= @customer.notes %></td>
     </tr>
     
+    <tr>
+        <th>Issues</th>
+        <td><%= @customer.issues.count %></td>
+    </tr>
+    
         <tr>
       <td/>
       <td>