Adding a whatsnew entry explaining 5224

Author: HGWright

docs/src/whatsnew/latest.rst

@@ -68,6 +68,9 @@ This document explains the changes made to Iris for this release
    dimension, when the scalar coord provided is already a dim coord.
    (:issue:`4415`, :pull:`5194`)
 
+#. `@HGWright`_ and `@trexfeathers`_ (reviewer) changed the way
+    :class:`CellMethod` are printed to be more CF compliant. (:pull:`5224`)
+
 
 💣 Incompatible Changes
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