Update the package docs for the new API layout (#1346)

codes/codes.go

@@ -12,14 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Package codes defines the canonical error codes used by OpenTelemetry.
-//
-// This package is currently in a pre-GA phase. Backwards incompatible changes
-// may be introduced in subsequent minor version releases as we work to track
-// the evolving OpenTelemetry specification and user feedback.
-//
-// It conforms to [the OpenTelemetry
-// specification](https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/trace/api.md#statuscanonicalcode).
 package codes // import "go.opentelemetry.io/otel/codes"
 
 import (

codes/doc.go

@@ -0,0 +1,25 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*
+Package codes defines the canonical error codes used by OpenTelemetry.
+
+This package is currently in a pre-GA phase. Backwards incompatible changes
+may be introduced in subsequent minor version releases as we work to track
+the evolving OpenTelemetry specification and user feedback.
+
+It conforms to [the OpenTelemetry
+specification](https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/trace/api.md#statuscanonicalcode).
+*/
+package codes // import "go.opentelemetry.io/otel/codes"