[meta] add auto-changelog

.npmrc

@@ -1 +1,3 @@
 package-lock=false
+allow-same-version=true
+message=v%s

CHANGELOG.md

@@ -1,3 +1,12 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+<!-- auto-changelog-above -->
+
 1.3.0 / 2022-04-11
 =================
   * [New] `shim`/`auto`: add `flat` to `Symbol.unscopables`

package.json

@@ -28,7 +28,9 @@
 		"posttest": "aud --production",
 		"tests-only": "nyc tape 'test/**/*.js'",
 		"lint": "eslint --ext=js,mjs .",
-		"postlint": "es-shim-api --bound"
+		"postlint": "es-shim-api --bound",
+		"version": "auto-changelog && git add CHANGELOG.md",
+		"postversion": "auto-changelog && git add CHANGELOG.md && git commit --no-edit --amend && git tag -f \"v$(node -e \"console.log(require('./package.json').version)\")\""
 	},
 	"repository": {
 		"type": "git",
@@ -94,6 +96,15 @@
 	"engines": {
 		"node": ">= 0.4"
 	},
+	"auto-changelog": {
+		"output": "CHANGELOG.md",
+		"template": "keepachangelog",
+		"unreleased": false,
+		"commitLimit": false,
+		"backfillLimit": false,
+		"hideCredit": true,
+		"startingVersion": "1.3.1"
+	},
 	"publishConfig": {
 		"ignore": [
 			".github/workflows"