DOC: update CHANGELOG

CHANGELOG.md

@@ -8,6 +8,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added (for new features, dependecies etc.)
 
+* two new field types for the form_elements module, `file` and `select`. See
+  the module documentation for more information.
+
 ### Changed (for changes in existing functionality)
 
 ### Deprecated (for soon-to-be removed features)