Add single doc.go file for package documentation

doc.go

@@ -0,0 +1,16 @@
+// Copyright (c) 2021 - The Event Horizon 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 eventhorizon is a CQRS/ES toolkit for Go.
+package eventhorizon

entity.go

@@ -12,7 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Package eventhorizon is a CQRS/ES toolkit.
 package eventhorizon
 
 import "github.com/google/uuid"

event.go

@@ -12,7 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Package eventhorizon is a CQRS/ES toolkit.
 package eventhorizon
 
 import (