Add CHANGELOG entry

CHANGELOG.md

@@ -78,6 +78,21 @@ govukRadios({
 
 This change was introduced in [pull request #4565: Allow `attributes` option on form groups](https://github.com/alphagov/govuk-frontend/pull/4565).
 
+#### Insert custom HTML into component form group wrappers
+
+You can now insert custom HTML into form group wrappers for all components with form fields.
+
+```njk
+govukRadios({
+  formGroup: {
+    beforeHtml: "example",
+    afterHtml: "example"
+  }
+})
+```
+
+This change was introduced in [pull request #4567: Add `beforeHtml` and `afterHtml` options to form groups](https://github.com/alphagov/govuk-frontend/pull/4567).
+
 #### Use tabular numbers with the `govuk-font-tabular-numbers` mixin
 
 You can now use tabular numbers in your authored Sass by including the new `govuk-font-tabular-numbers` mixin.