[meta] add auto-changelog

.npmrc

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

CHANGELOG.md

@@ -0,0 +1,6 @@
+# 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).

package.json

@@ -21,7 +21,9 @@
 		"pretest": "npm run lint",
 		"tests-only": "nyc tape 'test/**/*.js'",
 		"test": "npm run tests-only --",
-		"posttest": "aud --production"
+		"posttest": "aud --production",
+		"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",
@@ -43,11 +45,20 @@
 	"devDependencies": {
 		"@ljharb/eslint-config": "^17.5.1",
 		"aud": "^1.1.4",
+		"auto-changelog": "^2.2.1",
 		"es-value-fixtures": "^1.2.1",
 		"eslint": "^7.21.0",
 		"for-each": "^0.3.3",
 		"nyc": "^10.3.2",
 		"object-inspect": "^1.9.0",
 		"tape": "^5.2.2"
+	},
+	"auto-changelog": {
+		"output": "CHANGELOG.md",
+		"template": "keepachangelog",
+		"unreleased": false,
+		"commitLimit": false,
+		"backfillLimit": false,
+		"hideCredit": true
 	}
 }