Update comments regarding DOMContentLoaded listeners

We only bind to `pageshow` now (slight edit) since: ae75de1

packages/govuk-frontend/src/govuk/components/character-count/character-count.mjs

@@ -193,11 +193,13 @@ CharacterCount.prototype.init = function () {
   this.bindChangeEvents()
 
   // When the page is restored after navigating 'back' in some browsers the
-  // state of the character count is not restored until *after* the
-  // DOMContentLoaded event is fired, so we need to manually update it after the
-  // pageshow event.
+  // state of form controls is not restored until *after* the DOMContentLoaded
+  // event is fired, so we need to sync after the pageshow event.
   window.addEventListener('pageshow', this.updateCountMessage.bind(this))
 
+  // Although we've set up handlers to sync state on the pageshow event, init
+  // could be called after those events have fired, for example if they are
+  // added to the page dynamically, so update now too.
   this.updateCountMessage()
 }
 

packages/govuk-frontend/src/govuk/components/checkboxes/checkboxes.mjs

@@ -65,9 +65,9 @@ Checkboxes.prototype.init = function () {
   // event is fired, so we need to sync after the pageshow event.
   window.addEventListener('pageshow', this.syncAllConditionalReveals.bind(this))
 
-  // Although we've set up handlers to sync state on the pageshow or
-  // DOMContentLoaded event, init could be called after those events have fired,
-  // for example if they are added to the page dynamically, so sync now too.
+  // Although we've set up handlers to sync state on the pageshow event, init
+  // could be called after those events have fired, for example if they are
+  // added to the page dynamically, so sync now too.
   this.syncAllConditionalReveals()
 
   // Handle events

packages/govuk-frontend/src/govuk/components/radios/radios.mjs

@@ -65,9 +65,9 @@ Radios.prototype.init = function () {
   // event is fired, so we need to sync after the pageshow event.
   window.addEventListener('pageshow', this.syncAllConditionalReveals.bind(this))
 
-  // Although we've set up handlers to sync state on the pageshow or
-  // DOMContentLoaded event, init could be called after those events have fired,
-  // for example if they are added to the page dynamically, so sync now too.
+  // Although we've set up handlers to sync state on the pageshow event, init
+  // could be called after those events have fired, for example if they are
+  // added to the page dynamically, so sync now too.
   this.syncAllConditionalReveals()
 
   // Handle events