Add changelog entry

Author: colinrotherham

CHANGELOG.md

@@ -4,6 +4,34 @@
 
 Note: This release was created from the `support/10.x` branch.
 
+#### Add a 'small' Nunjucks option to buttons, checkboxes and radios
+
+We've added a new `small` Nunjucks option to buttons, checkboxes and radios as a simpler alternative to the small modifier class. For example:
+
+```patch
+  {{ button({
+    text: "Save and continue",
+-   classes: "nhsuk-button--small"
++   small: true
+  }) }}
+```
+
+```patch
+  {{ radios({
+    fieldset: {
+      legend: {
+        text: "How do you want to be contacted about this?",
+        size: "l"
+      }
+    },
+-   classes: "nhsuk-radios--small",
++   small: true,
+    items: []
+  }}
+```
+
+This was added in [pull request #1801: Add button, checkboxes and radios small option](https://github.com/nhsuk/nhsuk-frontend/pull/1801).
+
 ### :recycle: **Changes**
 
 #### Hide the character count messages when unnecessary