Add a changelog entry

Author: MrAlias

CHANGELOG.md

@@ -11,11 +11,27 @@ OpenTelemetry Go Automatic Instrumentation adheres to [Semantic Versioning](http
 ### Added
 
 - Cache offsets for `google.golang.org/grpc` `1.72.0-dev`. ([#1849](https://github.com/open-telemetry/opentelemetry-go-instrumentation/pull/1849))
+- The `go.opentelemtry.io/auto/handler` package is added.
+  This package contains interface definitions for types that want to handle the telemetry generated by auto-instrumentation. ([#1859](https://github.com/open-telemetry/opentelemetry-go-instrumentation/pull/1859))
+- The `go.opentelemtry.io/auto/handler/otelsdk` package is added.
+  This package a default handler that uses the OpenTelemetry Go SDK to handle telemetry generated by auto-instrumentation. ([#1859](https://github.com/open-telemetry/opentelemetry-go-instrumentation/pull/1859))
+- The `WithHandler` function is added to configure `Instrumentation` in `go.opentelemtry.io/auto` with the desired handler implementation. ([#1859](https://github.com/open-telemetry/opentelemetry-go-instrumentation/pull/1859))
+
+### Changed
+
+- The `WithEnv` function no longer parses `OTEL_SERVICE_NAME` or `OTEL_TRACES_EXPORTER`.
+  Use the `Handler` from `go.opentelemtry.io/auto/handler/otelsdk` with its own `WithEnv` to replace functionality. ([#1859](https://github.com/open-telemetry/opentelemetry-go-instrumentation/pull/1859))
 
 ### Removed
 
 - Build support for Go 1.22 has been removed.
   Use Go >= 1.23 to develop and build the project. ([#1841](https://github.com/open-telemetry/opentelemetry-go-instrumentation/pull/1841))
+- The `WithServiceName` function is removed from `go.opentelemtry.io/auto`
+  Use `WithServiceName` in `go.opentelemtry.io/auto/handler/otelsdk` along with `WithHandler` to replace functionality. ([#1859](https://github.com/open-telemetry/opentelemetry-go-instrumentation/pull/1859))
+- The `WithTraceExporter` function is removed from `go.opentelemtry.io/auto`
+  Use `WithTraceExporter` in `go.opentelemtry.io/auto/handler/otelsdk` along with `WithHandler` to replace functionality. ([#1859](https://github.com/open-telemetry/opentelemetry-go-instrumentation/pull/1859))
+- The `WithResourceAttributes` function is removed from `go.opentelemtry.io/auto`
+  Use `WithResourceAttributes` in `go.opentelemtry.io/auto/handler/otelsdk` along with `WithHandler` to replace functionality. ([#1859](https://github.com/open-telemetry/opentelemetry-go-instrumentation/pull/1859))
 
 ## [v0.21.0] - 2025-02-18