Merge branch 'aa-changelog-for-usage-data-metrics' into 'master'

Changelog for usage data metrics

See merge request gitlab-org/gitlab!44597

doc/development/changelog.md

@@ -48,6 +48,7 @@ the `author` field. GitLab team members **should not**.
 - Any docs-only changes **should not** have a changelog entry.
 - Any change behind a disabled feature flag **should not** have a changelog entry.
 - Any change behind an enabled feature flag **should** have a changelog entry.
+- Any change that adds new usage data metrics and changes that needs to be documented in Product Analytics [Event Dictionary](telemetry/event_dictionary.md) **should** have a changelog entry.
 - A change that [removes a feature flag](feature_flags/development.md) **should** have a changelog entry -
   only if the feature flag did not default to true already.
 - A fix for a regression introduced and then fixed in the same release (i.e.,