Fix replacement column not showing (escape HTML)

Author: iYassr

docs/app/index.html

@@ -1180,7 +1180,7 @@ <h3>Sanitized</h3>
           <tr>
             <td><span class="detection-type type-${d.type}">${d.type}</span></td>
             <td><code>${escapeHtml(d.text)}</code></td>
-            <td><code>${d.placeholder}</code></td>
+            <td><code>${escapeHtml(d.placeholder)}</code></td>
             <td>
               <div class="confidence">
                 <div class="confidence-bar">