Add missing changelog entry

Refs: #2902

Author: kdeldycke

CHANGES.rst

@@ -54,6 +54,8 @@ Unreleased
     commands. :issue:`3107` :pr:`3228`
 -   Add ``click.get_pager_file`` for file-like access to an output
     pager. :pr:`1572`
+-   Mark additional built-in strings with ``gettext()`` to extend translation
+    coverage. :pr:`2902`
 
 Version 8.3.3
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