unit: move code generation to unit package
MODIFY
unit/doc.go
unit/doc.go
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
-//go:generate go run internal/autogen.go
+//go:generate go run generate_unit.go
// Package unit provides a set of types and constants that facilitate
// the use of the International System of Units (SI).

RENAME
unit/internal/autogen.go
unit/generate_unit.go
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
+// +build ignore
+
package main
import (

unit: move code generation to unit package