Move inline JS to application.js.

site/content/docs/4.3/forms/checks.md

@@ -14,13 +14,6 @@ Structurally, our `<input>`s and `<label>`s are sibling elements as opposed to a
 
 Our checks use custom Bootstrap icons to indicate checked or indeterminate states.
 
-<script>
-document.addEventListener("DOMContentLoaded", function() {
-  var checkbox = document.getElementById("flexCheckIndeterminate");
-  checkbox.indeterminate = true;
-});
-</script>
-
 ## Checks
 
 {{< example >}}

site/static/docs/4.3/assets/js/src/application.js

@@ -19,6 +19,16 @@
     return [].slice.call(list)
   }
 
+  (function () {
+    var checkbox = document.getElementById('flexCheckIndeterminate')
+
+    if (!checkbox) {
+      return
+    }
+
+    checkbox.indeterminate = true
+  })()
+
   makeArray(document.querySelectorAll('.js-sidenav-group'))
     .forEach(function (sidenavGroup) {
       var groupHasLinks = Boolean(sidenavGroup.querySelector('li'))