Add an entry for changelog

Author: shalevr

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 - Use BoundedAttributes instead of raw dict to extract attributes from LogRecord and Support dropped_attributes_count in LogRecord ([#3310](https://github.com/open-telemetry/opentelemetry-python/pull/3310))
+- Add unit to view instrument selection criteria
+  ([#3341](https://github.com/open-telemetry/opentelemetry-python/pull/3341))
+
 ## Version 1.18.0/0.39b0 (2023-05-04)
 
 - Select histogram aggregation with an environment variable