Docs: Use ESM Popper CDN reference in 'Using Boottrap as a module'

Author: julien-deramond

config.yml

@@ -82,6 +82,7 @@ params:
     js_bundle_hash:   "sha384-w76AqPfDkMBDXo30jS1Sgez6pr3x5MlQ1ZAGC+nuZB+EYdgRZgiwxhTBTkF7CXvN"
     popper:           "https://cdn.jsdelivr.net/npm/@popperjs/core@2.11.6/dist/umd/popper.min.js"
     popper_hash:      "sha384-oBqDVmMz9ATKxIep9tiCxS/Z9fNfEXiDAYTujMAeBAsjFuCZSmKbSSUnQlmh/jp3"
+    popper_esm:       "https://cdn.jsdelivr.net/npm/@popperjs/core@2.11.6/dist/esm/popper.min.js"
 
   anchors:
     min: 2

site/content/docs/5.3/getting-started/javascript.md

@@ -71,7 +71,7 @@ To fix this, you can use an `importmap` to resolve the arbitrary module names to
     <script type="importmap">
     {
       "imports": {
-        "@popperjs/core": "{{< param "cdn.popper" >}}",
+        "@popperjs/core": "{{< param "cdn.popper_esm" >}}",
         "bootstrap": "https://cdn.jsdelivr.net/npm/bootstrap@{{< param "current_version" >}}/dist/js/bootstrap.esm.min.js"
       }
     }