Update changelog

CHANGELOG.md

@@ -8,6 +8,14 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ## [Unreleased]
 
+## [1.15.0-rc.1/0.38.0-rc.1] 2023-03-01
+
+This is a release candidate for the v1.15.0/v0.38.0 release.
+That release will include the `v1` release of the OpenTelemetry Go metric API and will provide stability guarantees of that API.
+See our [versioning policy](VERSIONING.md) for more information about these stability guarantees.
+
+This release drops the compatibility guarantee of [Go 1.18].
+
 ### Added
 
 - Support global `MeterProvider` in `go.opentelemetry.io/otel`. (#3818)
@@ -2327,7 +2335,8 @@ It contains api and sdk for trace and meter.
 - CircleCI build CI manifest files.
 - CODEOWNERS file to track owners of this project.
 
-[Unreleased]: https://github.com/open-telemetry/opentelemetry-go/compare/v1.14.0...HEAD
+[Unreleased]: https://github.com/open-telemetry/opentelemetry-go/compare/v1.15.0-rc.1...HEAD
+[1.15.0-rc.1/0.38.0-rc.1]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.15.0-rc.1
 [1.14.0/0.37.0/0.0.4]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.14.0
 [1.13.0/0.36.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.13.0
 [1.12.0/0.35.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.12.0