Add a changelog entry for the Locale export.

PiperOrigin-RevId: 285194103
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 21c928b..21b4246 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@
  * Change plural behavior with floating point howMany argument so that doubles
    that are equal to integers print the same as the integer 1. That is, '1
    dollar', rather than '1.0 dollars'.
+ * Add package:intl/locale.dart that exports a standards-compliant Locale class.
 
 ## 0.16.0
  * Fix 'k' formatting (1 to 24 hours) which incorrectly showed 0 to 23.